Welcome back to my continuing quest to show off the home computer era (which roughly lasted from 1975 to 1994) and its enormous variety of wondrous MOS6502 based machines!

This time, I’ll be taking a look at a relatively obscure machine released by Commodore during a time of management turmoil. They had just ousted Jack Tramiel from the board and where clearly still in some disarray.

The result of all this turmoil was the Commodore Plus/4 - a high spec machine based on a low cost/spec design. It was released by Commodore in 1984 and portrayed by the company as a business alternative / successor to the Commodore 64.
Commodore Plus/4 liquidation advert, 1986 (source: www.commodore.ca)
Above: by 1986, the Commodore Plus/4 was available for just $79.
Sadly, the market disagreed and the machine was an almost complete failure. While it had some succes in Europe*, its sales where so poor worldwide that it (and indeed the entire line of machines based on the TED architecture) was cancelled by Commodore only a year after being put into production.

This was in part due to Commodore ’doing a 180’ on price. Originally TED based machines where envisioned by Jack Tramiel to be sold for less than $50, but post-Tramiel Commodore decided to release this machine based on the TED design for $299 instead.

Mainly, however, it was due to the fact that the new machine was in many ways less capable than the machine it was supposed to replace / complement: the Commodore 64**.

It’s a shame the Plus/4 didn’t catch on, as setting aside the lack of sprites and slightly lackluster sound output, the machine is rather capable and a nice addition to the Commodore 8-bit family.

Aside from its 64KB of RAM, it features the same 320x200 / 160x200 resolutions that the Commodore 64 has - but has 121*** different colours to pick from instead of merely 16. It also has a MOS-6502 derived (and fully 6502 compatible) MOS 8501 as a CPU, running at 1.76Mhz, which makes it quite a bit faster than the Commodore 64.

Unlike the older Commodore models such as the VIC and C64, it features a BASIC language with lots of commands to access graphics and sounds. It also features a much faster native disk drive then the Commodore 64 and can access almost all memory for BASIC (about 60KB, rather than the 38KB the Commodore 64 can access). All this adds up to a rather capable little machine, especially for non-gaming purposes.

Uniquely, it comes with a ’full productivity suite’ in ROM, containing four programs (hence the ’Plus/4’): a word processor, a database, a spreadsheet and a graphing program. These even allow you to copy and paste data between them, which was quite an advanced feature at the time.

Sadly, other than the nifty copy and paste feature, the programs included are not very good.

The word processor limits you to 99 lines and you'll need to scroll horizontally to see the full line, the spreadsheet is frustratingly limited, the graphing software is very basic and the database isn’t really any good either. Adding insult to injury, the software is also slow and unstable.
Why it is interesting:
  • Despite its other limits, it has the largest colour palette of all of the officially released Commodore 8-bit machines. As a result, some of the pictures created on it are very nice!
  • It comes with a rather complete version of BASIC (v3.5), which formed the base for the equally nice BASIC v7.0 in the Commodore 128.
  • The Plus/4’s graphics and sound chip has some interesting features, which allow for some very cool demo effects of types not usually seen on the other 8-bit Commodores.
  • Irvin Gould named the Commodore Plus/4’s low market performance as one of his reasons for cancelling the Commodore 65 project.
Notable software includes:
  • Mercenary - Escape From Targ, a smoother version of the Commodore 64 classic wireframe game.
  • Treasure Island - one of the better action adventures on the Commodore Plus/4.
  • Adventures in Time - a colourful platformer released in 2010 (on floppy disk!) by Psytronik.
Some Commodore Plus/4 trivia:
  • The Commodore Plus/4 is the ’top end model’ of the Commodore ’TED’ range, consisting of the Commodore 16, the Commodore 116 and the Commodore Plus/4.
  • Originally, you where supposed to be able to select between multiple different in-ROM software options. This turned out to be infeasible, so all Plus/4’s have the same built-in suite.
  • Once the machine had been slashed in price to $79, it sold quite well. Ironically, the original TED machine was designed to be sub-$50 in price but was later re-envisioned as a number of more expensive systems, including the Plus/4 which was put on the market at $299. If Commodore had started the Plus/4 at a price of $79, it probably would have sold a whole lot better!
  • It was also disparagingly called the ’Minus/60’ by less than positive Commodore 64 owners & fans (because of the lesser gaming abilities of the machine and it being incompatible with the C64)!
Interesting sites about the Commodore Plus/4 include:
  • The wonderful Plus 4 World, where you can find forums, games and more!
  • The equally wonderful commodore16.com, which is about the smaller, compatible, sibling of the Plus/4: the Commodore 16.
  • For additional information about the Commodore Plus/4 and its siblings, visit floodgap.com
Personal notes about the Commodore Plus/4:
  • When I owned my first Commodore 64, I’d regularly see BASIC program listings for the Commodore Plus/4 in my Dutch magazine of choice (Commodore Info) and wonder what the machine could do with all those neat-o graphics and sound commands available.
  • I drove 80km through winter weather, complete with unexpected snowfall and sleet to get my Commodore Plus 4. It took me 20 minutes to find the address as my TomTom didn’t have an up to date map. I’m still happy I did it though, it’s a nice and unique 8-bit machine!
  • Seeing the machine in use, I always find myself wondering what 8-bit computing would have been like if Commodore had made the Commodore 128 with more of the Plus/4 features added in (such as the extra colours and higher CPU speed) on top of the base Commodore 64 capabilities, instead of the Z80/CPM stuff they ended up with.
*) Commodore produced about 400.000 Commodore Plus/4’s, of which 150.000 where sold in the USA. Of the remainder, most where sold in Europe. Source: www.commodore.ca

**) It did not have sprites, it had much worse sound capabilities, its BASIC ran slower (though the machine itself is faster when programmed in machine language) and it had more restrictions on its multi-colour graphics modes. It was also incompatible with Commodore 64 (so software had to be rewritten), though hardware was mostly compatible - but not always.

***) Well, the adverts state it has 128 colours available. But what the adverts don’t state is that 8 of those are ’shades of black’.

Which are all, errr, pure black. Truth in advertising then - and it did lead to lots of ’eight shades of black’ jokes and at least one (rather good) demo, so it’s not all bad!