Comparison/evaluation of some homecomputers from 1980-1985
Note: this page is not nearly finished and may be inaccurate in a few places.
The BBC B was my first computer and also the first usable computer I had access to (contrary to what you might expect, I didn't find my dad's ZX80 usable ;-) ), and remains my favourite 8 bit machine after trying out a bunch of others... (nostalgia would probably prevent any other machine becoming favourite, but, I'm not blind to the negative points of this machine, nor to the positive points of others)
I loaned a bunch of machines with software, books and add-on hardware from a friend, and was given a few others (ZX spectrum & ZX81). On this page I will compare and give the good and bad points of the BBC B and the other machines that I tried (mostly during 2001-2002). All this from a perspective of 1983/1984 where that's relevant (e.g. prices), or the entire period up to the machine was released (i.e. using all machines released up to that time and the ones that would appear shortly after as a benchmark) for criticism on functional specifications.
The bad points outnumber the good points for all the machines in this list! That's probably just because of my emphasis on programmability and user friendliness... But, they are all real bad points and as you can see, there are no machines that are good in all aspects. They all have large problems and it's obvious that no single machine at the time could be recommended for all people. I remember I had a hard time choosing a computer in 1983, and this page shows that was inevitable!
If you have any suggestions, comments or good- or bad points that should be mentioned, send me a mail!
I tried the listed machines imagining:
- it was 1982-1984
- and not knowing a lot about computers
to see if I liked them, the manuals etc. For this, it is nice to have a machine in the original box, you can then really get into the mood of "I just bought this new computer, lets see what I can do with it" :-)
Note: with 'gbp' I mean the £ (UK)
List order in date of release of the machine:
Specs: Real keyboard, 24K ROM, 48K RAM,...
I still haven't found one so I can't tell anything about it from experience!
Specs: membrane keyboard, 1K RAM, 4K ROM...
All comments at the moment are my thoughts about it at the time:
This was my dad's, and the first computer I used. I was NOT impressed! I remember the screen flickering at each key press and totally being gone during program execution. Integer calculations only. There was a later 8K Basic extension with most of the functions of the ZX81, including floating point calculations (I believe only the slow-mode was not available in such an upgraded ZX80); This upgrade was probably from the time of the ZX81, or was it released before the ZX81?
I remembered something else that's quite funny: When we first used it, I thought the machine was broken, because the screen display went away at keypresses. So, my dad phoned the shop (somewhere in Rotterdam, where it was quite cheap, presumably because the ZX81 had just been introduced, or maybe it was a trade in, as it didn't come with a box), and found out that that was normal for the ZX80! Only the ZX81 had the option to give a display at all times. Imagine that, you're sure the computer is broken, then it turns out this is normal...
Specs: Real keyboard, 1MHz 6502, 2K RAM + 8K ROM minimum, expandable to 12K RAM + 16K ROM for a standard tape machine, or 15K RAM + 20K ROM for a machine with disc pack (the disc pack includes another 3K RAM for workspace and 4K DOS ROM); Further expansion is possible by whatever you place in the externally mapped (offcard, usually external but can be placed internally too) space. Other expansions include a BBC Basic conversion card (incompatible with the disc pack btw.) and a colour card.
Introduced mid 1980, this machine does not have colour, and very limited sound. It has a reasonable keyboard in early models and a good one in later models, provides good facilities for programming and for expansion, but it's clearly not a desirable machine for people contemplating buying a computer in 1983/1984, who often wanted to play games. This is a DIY computer, with lots of technical information provided standard in the 'technical manual'. Mid 1982 it was essentially obsolete, superseded by the BBC model A, Commodore 64 and Sinclair Spectrum.
- Keyboard is better than almost all other similarly priced machines from 1980-1981; well, the later type at least. The earlier type that's used up to issue 4 PCB machines, uses contact strips that corrode after a while giving erratic contact, resulting in unrecognised keypresses and keyboard bounce.
- Indestructible case!
- Very crisp TV/composite output
- Built in assembler (but two pass assembly for forward references is poor in my experience, see below)
- Manual is good, and it comes with the 'technical manual'.
- Rather little commercial software, books and hardware add-ons were available.
- White/beige plastic yellowes...
- No n-key rollover, so if you're typing with more than 1 finger, and type in the word 'CLEAR' for example, you will end up with something like 'CLER'. I have to force myself to slow down when typing on the Atom or the result is a mess...
- No lower case display
- No colour, primitive sound. Fine for 1980-1981, but this makes it distinctly old fashioned later on. Add-on colour boards exist, but these are usually for TV output only (no RGB monitor), and the display quality is poor (I've tried 2 Acorn colour cards and one didn't give any proper TV output, the other no colour and synchronisation problems in graphics mode. The RGBsync outputs (you need to solder wires to them yourself, not a standard output) on one work on a SCART TV, but give noise pixels on a Microvitec CUB (TTL RGB), this probably means the RGB signal is of poor quality too. If this is typical of these cards then I understand why these cards were not thought highly of! UPDATE: I tried on another, newer CUB monitor with plastic case, and this had no problems with the signal. I'm still sure the RGB signal is of poor quality, as the other CUB works fine on my BBC computer. I don't have an oscilloscope, so I can't give precise information on the signal quality).
- External power supply
- 2K RAM isn't enough for anything other than extremely short programs, so expansion is a must for any serious use.
- The video output is 60Hz, as it uses the 6847 video processor. This makes it incompatible with various TVs and monitors which are often fixed to handle 50Hz inputs only. I've seen estimates that 1/3 of all TV's and monitors can't handle the Atom's 60Hz output, I've seen it myself on one of 3 monochrome monitors I tried.
- Variables have extremely restrictive names (A-Z for integers, AA-ZZ for arrays)
- 2 pass assembly for forward references is poor, in my experience: I got weird errors when adding lines. May be related to the Atom not clearing variables at RUN. I worked around this by explicitly setting all labels to -1 in the program before getting to the assembly part.
Verdict: For 1980-1981 a good machine. Obsolete when the BBC computer and the ZX Spectrum arrived.
Specs: membrane keyboard, 1 K RAM, 8 K ROM, RAM expandable with e.g. the standard 16K RAM pack.
The keyboard is awful, but with the floating point variables and the slow mode that gives a screen image while running a program (or just pressing a key!) this is much more usable than a ZX-80, from what I remember from that machine, long time ago! This machine is not at all comparable to the other homecomputers, the keyboard makes this just barely usable, adding a proper keyboard would have cost so much that it would have been more prudent to buy say, an Acorn Atom... (except that the ZX81 had much more commercial support, although I'm not sure if much of this may have come at a time when neither the ZX81 nor the Atom were of interest to new buyers, say mid 1982 on? Check...
- Black plastic doesn't yellow...
- Plenty of commercial software, books and hardware add-ons were available.
- Barely usable keyboard, seems worse than what I remember of the ZX-80
- External power supply
- 1K RAM isn't enough for anything other than extremely short programs.
- Very poor TV output
- RAM pack wobble :->
Verdict: It was cheap, and that's about the only good point. A programmable calculator was cheaper, more powerful for many purposes and had just as much memory. When the ZX Spectrum arrived mid 1982, there really was no reason to buy a ZX81.
Acorn BBC B
Specs: Real keyboard, 32K RAM, 32K ROM, expandable with 3x16K sideway ROMs, more with a ROM expansion board. Other internal expansions that appeared later are shadow RAM boards (screen RAM no longer uses up main memory) and 4MHz accelerator boards.
Excellent computer, but too expensive. Not enough RAM. It should have come standard with 16K sideway RAM, which would have provided enormous potential for large games. Perhaps even 64K total, with the OS copied to RAM or swapped in/out as with paged ROMs (the C64 can do that).
To reduce cost, the main PCB should not have had the provisions for the econet and diskinterfaces, but instead slots as used on the Apple 2 and Atari 400/800. The model A should have come with 32K RAM and with the PCB simplification it could probably have been sold for the original 235 gbp, perhaps a bit more. It probably would have been more succesful than the model B in that case... Btw, I'm sure the models A & B could both have been sold for less anyway; there's an interview with an Acorn guy in an Asterisk (dutch) where he talked about the money wasted at Acorn (sending a BBC computer by taxi to a dealer a hundred kilometres or so away, that sort of thing).
- Good keyboard
- Internal power supply
- Hi-res graphics (easy to use, but there's no circle or flood fill command)
- Good Basic with integrated assembler
- 2MHz 6502 (fast for late 1981 and early 1982, standard speed for 1983)
- Manual (at least when the 'real' manual was ready, early machines came with a 'provisional manual')
- Ready to use hardware interfacing connectors
- Tape loading system; files are loaded/saved in blocks with error detection and "rewind tape" messages etc.
- White/beige plastic yellowes...
- Too expensive
- Not enough RAM
- TTL RGB only (and no TTL intensity signal). This means just 8 colours even in the 4 bits per pixel mode.
- TV output is not very crisp (other machines like the Atari 800XL and the Acorn Atom give a fantastically sharp image on my 37cm TV)
- It gets too hot (the internal power supply is not helping, but that's not really an excuse; although the power supply itself does not appear to be very efficient (perhaps it wasn't possible to make them better at the time), Acorn should have given the power supply much more ventilation space). On my main BBC, when it's heated up after 15 minutes or so, the TV output becomes black & white! (The RGB output is not affected)
- Case is not stiff enough
- Case is too big, esp. too wide. The cartridge slot should have gone elsewhere than left of the keys.
- Acorn's arrogant attitude. This resulted in them keeping prices high because 'enough machines were being sold at the current price' and downplaying any achievements by other manufacturers as being less than Acorn's or even 'we can have that much free RAM too, with an added second processor', but those second processors weren't available...
This rubbed off on the supporting companies who liked to do a lot of negative advertising like 'this is buffered unlike the inferior products from our competitors'. Watford electronics is particularly irritating in this respect. It makes me feel sick.
- Software for the BBC was more expensive than for the Spectrum/C64.
- Hardware prices were usually higher than for other machines as well. Some prices were insanely high, like the Aries 20K shadow RAM board for 100 gbp. 100 gbp? That was about the price of a complete Oric 1 or 16K Sinclair Spectrum...
Verdict: Best programming machine until late 1985, but from early 1984 on it was definitely too expensive and more powerful machines already appeared (Sinclair QL). Acorn sat on their laurels, relying on the money guaranteed from the educational support schemes (schools would have to pay just part of the expense of the hardware, government paying the rest) and did not develop successors/upgraded versions in time.
Commodore 64 (C64)
Specs: 1MHz 6510 CPU (almost the same as the 6502), 64K RAM, 24K ROM, real keyboard.
Good hardware (64K RAM, all usable through mapping, good sound, reasonable keyboard (mushy feel)), good value for money:
- 64K RAM
- The best sound hardware of any home computer
- Lots of commercial software, probably the most of any 8 bit micro
- Lots of commercial hardware
- Magazines and books abound on the internals, esp. in German
- Atrocious operating system and Basic
- Proprietary expansion connectors: You want to connect a standard cassette recorder? Forget it!
- Serial disk interface. The OS actually provides an abstraction for any mass storage device (serial channels, with the details handled in the peripheral itself), but the commands to handle this are clumsy; with very little extra basic/os support this could have been much better and thus have been a 'cool feature' of the C64. Also, disk loading/saving is sloooow!
- It's ugly! (the shape and those awful brownish colours). At least yellowing isn't a problem :->
- The computer and all peripherals come with external power supplies. Sheesh, haven't these people thought this out? With a few peripherals there are more cables and boxes than in a elementary particle accelerator (solution would have been: internal PS for each device, or a single large PS capable of handling lots of peripherals).
- 1MHz 6510 (almost the same as the 6502), rather slow when most machines introduced around the time of the C64 were using 2MHz 6502s or 4MHz Z80s.
- Edge connectors for user port etc.
- Manual. For serious programming you need to buy the separately sold 'Programmers reference manual'.
Verdict: It's no fun programming with this machine, a shame as the hardware provides enormous potential, with RAM/ROM mapping done mostly the right way (no facility for multiple paged roms though). Extensions like Simon's Basic exist which are good, but non standard so you can't exchange programs with other people, and magazines will only provide listings in the crappy standard Basic. So, a good machine to play games but for developing programs it's useless (unless you were/wanted to be a commercial programmer).
Sinclair ZX Spectrum
Specs: Membrane with rubber keys, 16K or 48K RAM, 16K ROM (Basic + OS), Z80 CPU
Fill in... (Need to play more with it and read some more books!)
- Small! Doesn't take up much space on say a table, which is good
- Black plastic doesn't yellow!
- Lots of commercial software
- Lots of commercial hardware expansions
- Poor keyboard, although it's not all that bad, really. You get used to the combinations, but it certainly is more tiresome than a real keyboard and touch typing is out of the question.
- External power supply.
Verdict: Good to learn programming and play games, overall the Spectrum is probably the best all round machine during 1982-1984 when one regards its cost, playing games, usefulness for programming and learning about computers.
The precursor of this machine is the Ti 99/4 which has a simpler keyboard, not as good as the proper one on the 4a. Basic is very slow. An example: 6 sines calculated per second whereas a BBC micro does 40/s albeit at reduced accuracy. The accuracy can only account for a part of this speed difference. The CPU is 16 bit but has no real internal registers which kills some of the speed. Still, reports say a tms9900 is faster and has smaller equivalent machine code programs than a 8086. One problem is that in this machine only the ROM and a little bit of the RAM is 16 bits wide. The rest of RAM is 8 bits wide so many reads/writes need to be done in 2 pieces.
Haven't found good information on the tms9900 assembly language to see for myself what the speed would be for a given program implemented in tms9900 asm. Anyone have some assembler reference on the web?
- External power supply
- Separate TV modulator (all those loose boxes with computers are really annoying)
- Only Ti peripherals can be used
Specs: Real keyboard, 32K RAM, 32K ROM, 2MHz 6502 CPU (not 1.79 MHz as various collectors say on their 'bragging lists'), no joystick ports, no cartridges/ROM expansion without an expansion unit.
The keyboard is better than the BBC's keyboard (at least for the BBC's standard type1 keyboard! for type 4 it may be a draw), and visually it is more attractive than the BBC micro; unfortunately those are all the good points compared to the BBC. The speed is awfully low, it's not faster than an Acorn Atom in most cases (but it does have good colour which the Atom doesn't have). Speed wise it's worst in the hi-res modes, where machine code will run 4.3 times slower than on a BBC (making it equivalent to a computer with 0.46 MHz 6502!). This really disappointed me. When I was looking for a machine in 1983, this was not apparent from reviews except in Acorn User (which I would not have bought/glanced at, not having any Acorn machine yet). I remember doing a speed test in mid 1984 at the dealer where I bought my BBC micro who had a computer attic, using a simple Basic loop, and being very disappointed by the 3x or so slow down in hi-res modes, but the 4.3 times for machine code makes the hi-res/hi-colours modes just about useless for anything! In the Basic speed tests, the Electron fares ok, but as ROM is accessed much faster than RAM (in particular because each byte has to be fetched in 2 goes, memory is organised 4 bits wide. What the hell were you thinking of when designing that, Acorn?), this is not a useful speed comparison for games. The result is that games for the Electron usually use MODE 5 (4 colours at 160x256) instead of MODE 2 (8/16 colours at 160x256) on the BBC, and still run slower. The slowness really shows even for games that use a 10K mode: E.g. Arcadians shows serious slowing down from 10.000 points onwards when multiple nasties come swooping down. On other games, the main problem is the lack of colours, they look very very dull compared to BBC versions. Sound is not great as there's just one channel, but this would not be much of an issue for most buyers, although other machines like the C64 and Atari 600XL provided good sound and generally superior abilities for game playing compared to the Electron for about the same price.
- Keyboard; some annoyances though, like the BREAK key positioned such that it's very likely you'll accidentally hit it when you don't want to, e.g. playing a game (esp. Elite).
- Inherited from the BBC computer: Hi-res graphics (easy to use, but there's no circle or flood fill command)
- Inherited from the BBC computer: BBC Basic with integrated assembler
- Inherited from the BBC computer: Tape loading system; files are loaded/saved in blocks with error detection and "rewind tape" messages etc.
- White/beige plastic yellowes...
- Uses an external power supply
- Inherited from the BBC computer: Not enough RAM
- Inherited from the BBC computer: TTL RGB only. This means just 8 colours even in the 4 bits per pixel mode.
- No joystick input. Adding a switched joystick interface would have cost almost nothing, and been much more useful than say the RGB output for a machine in this price class.
- For the market the Electron was intended, it should also have included a cartridge socket.
- For 1983: Price upped from the expected/announced 150 gbp to 200gbp when the machine finally arrived. This was when all other hardware was getting cheaper... Acorn arrogance ('we're not in the discounting business' type statements) prevented this getting sold at lower prices prior to it being too late, thus Acorn killed their own market, and if it were not for Olivetti stepping in in 1985, they would not have survived (because of this attitude and the resulting inability to gauge the market). I think the BBC should have awarded the 1984 contract to Sinclair... This would have done both companies good, esp. kicking Acorn in the ass and making them pay more attention.
- Very slow hardware. The ROM based rountines are usually fast (i.e. in all but the 20K screen modes), but that's useless for machine code games. The result is that the hi-res graphics are virtually useless except for your own plotting programs; if you're prepared to wait a really long time.
- Saving data or programs to cassette in screen MODEs 0,1,2,3 when a Plus 1 expansion is attached can lead to data loss (of the data/program being saved, not the data/program in memory)! I presume because the electron is slowed down so much in hi-res modes... This is insane!
- When accessing disks (Plus3 or Solidisk's EFS, others possibly too), the screen is switched off! Not much of an improvement on the ZX80 here...
- it produces a lot of interference on TV (more than my BBC), i.e. when the computer is switched on but you're watching TV. And this is the german version that has copper plates shielding it!
- The much advertised compatibility with the BBC microcomputer is almost useless due the enormous speed difference, and to a lesser extent the absence of the 1K screen mode 7 (teletext).
- Acorn's attitude; see the BBC section.
Verdict: A useless machine.
Virtually identical to the 800XL. 16K RAM, case is less deep. Slightly cheaper,the 600XL appeared a few months before the 800XL. See the 800XL description for more information.
Specs: Real keyboard, 64K RAM (not sure if all is usable, is the OS copied to RAM?), 16K ROM (OS + Basic), 1.79MHz 6502 (why this weird speed? I've seen it with various Z80 machine too: 3.58 MHz (factor 2); looks like being related to video clock speed so that no special delay circuitry is necessary to handle CPU/graphics chip RAM access clashes).
- Good value for money (late 1983/early 1984)
- Good keyboard
- Very crisp TV output (the best of the 8 bit machines I've seen)
- The white/beige plastic part of the case yellowes...
- External power supply
- The highest resolution mode 320x192 is only available in 2 colours, this is too little for the time, showing its age (this machine being largely identical to the Atari 400/800 series from 1979). [ yes, I know palette changes can be set at any scanline. But vertical separation is only feasable for some games/purposes, so this does not eliminate the need for more colours per scanline. 'Thrust' for example is extremely blocky compared to the BBC version. ]
- For disks: the disk OS has to be booted from disk. Rather annoying compared to the ROM based DOS in the BBC.
- Very expensive software
- Only atari peripherals can be connected via the proprietary serial bus
- The 'manual' is a joke. A couple of pages setting it up, a brief bit about Basic programming, that's it. You really need to buy a real manual immediately (at least good books were long available due to the similarity with 400/800 series)
Verdict: Appeared too late. It's specifications were just about ok at the end of 1983, but that's all. It was basically an already 4 year old design, showing its age, and soon being completely overtaken. So, all in all: superfluous.
Specs: 128K RAM, 48K ROM, 4MHz Z80 CPU, membrane keyboard with moving keys.
- Very high resolution graphics
- The disk system is probably one of the best on home computers. I don't like the need for a boot disk though. Why not DOS in ROM?
- Built in word processor
- The built in joystick is quite useful for text/program editing
- Keyboard. Not just the poor feeling, the construction with the keyboard and connection being a single easily damaged membrane is very bad.
- external power supply.
- The Basic is slooooow...
- When it finally arrived (the 64K version end of 1984, 128K beginning of 1985, about a year and a half later than it should have), it was too late and about to be overtaken by 16 bit machines (in fact already overtaken by the QL, despite that machine's problems).
- Edge connectors for printer/monitor etc. Try getting hold of such connectors now!
- Commercial software: There's not much of it is there?
Verdict: Sounded good at the end of 1983, actually useless at the end of 1984/beginning of 1985.
Other machines I will not dive deeply into for the reasons given:
The ridiculously high price makes any positive points just about irrelevant, but I'll name one: The case is good for expansion, with room for internal cards just as with PCs.
Later machines, introduced 1985-1986
- Acorn BBC B+/B+128K (mid/late 1985): Very bad idea. Very little improvement over the B, price (500 gbp) is ridiculously high for the time. The B+128K should have been introduced early 1984, for the same price as a BBC B (400 gbp). The disk interface and extra RAM surely could have been included at no extra cost considering the savings made from redesigning the circuit board, soldering chips directly on the PCB etc (most of the BBC B's disk interface cost came from the 8271). In that case, it could have made a big impact.
- Acorn BBC master (ca. feb 1986): Too wide, far too expensive (500 gbp for the bare machine, you'd need to add a diskdrive and monitor; for the same price you could buy an Atari ST), ugly (that's what I think of it anyway), awful name, probably coming from Acorn's arrogance. Surprisingly successful, which it really shouldn't have been. Designing an 8 bit machine in 1984-1985 was moronic, and it's not even cool like the Apple IIGS. Another bad thing is the tiny prongs on the top section of the case that easily snap off.
- Acorn BBC master compact: I didn't follow the Acorn stuff any more from 1985, and on reading the ads for the master/master compact in general mags (HCC nieuwsbrief for example) I couldn't believe Acorn was this stupid. The master was bad enough, the compact is a completely useless machine (3.5 drive and no cassette port means you're screwed if you want to use commercial software; and it's not actually compact, is it? Again too expensive compared to the Atari ST and Commodore Amiga).
- Apple IIGS: Introduced in 1986 for a price for which one could buy an Atari ST or Commodore Amiga, this machine has a certain coolness because of:
- Very nice styling
- Expansion card capability
- 65SC816 with more instructions and larger address space than a standard 6502.
Last modified: Thu Nov 1 23:53:24 CET 2012