This PERITEL Atari 800 computer was officially released by Atari in France, probably in Q3-Q4 1982. It is not the DIY project of a fan, as demonstrated by the additional Atari components with specific Atari references (see below) and the very existence of several "Version PERITEL" French tapes (see below), such as:
- CX4101 BASIC PERITEL, Initiation à la programmation en Langage BASIC I
- CX4123 BASIC PERITEL, Centrale nucléaire Version 16 Ko & Version 32 Ko
These specific "Version PERITEL" tapes were required to accommodate the unusual colour palette produced by this PERITEL circuitry.
As explained on the PAL Atari 800XL page, France was neither a PAL nor NTSC but a SECAM country. So, Atari France had to find a workaround to sell the Atari 400 & 800 computers locally, despite the lack of SECAM versions. The quick fix was to mod a PAL computer to add an RGB signal, generated in an additional PERITEL daughterboard-card, available in a PERITEL/SCART connector. This brings the total number of video cables for this machine to 3, and the total number of video signals to 4:
- Monitor (video composite aka CVBS or S-Video aka YC)
- PERITEL (in RGB mode)
On the PERITEL Atari 800, the cable is detachable and plugged into the computer, in a DIN 8-Pin connector. On the PERITEL Atari 400, the cable is not detachable. Consequently, it is even more difficult today to find a PERITEL Atari 800 with its PERITEL cable – which was often lost.
Aesthetically, the PERITEL version can be spotted by the additional DIN 8-Pin connector on the left side of the computer (usually without any connector there). If you are very lucky, a PERITEL hand-written sticker will also be present on the bottom.
I am the happy owner of 3 of these machines, with two different revisions of the model. They all came fitted with 48Kb (and the PAL OS cartridge CX801-P), with or without protective plastic shells, surely to reduce the heat.
2 revisions (at least?)
Among my 3 machines, I noticed two different revisions:
- One that came with "CO61131 REV.A" stamped inside the chassis, with the "CAO61034" PERITEL adaptor, (c) 1982, ICTv 12-82.
- One that came with "CO61131 REV.X2A" stamped inside the chassis, with the "CAO61034 REV.X1A" PERITEL adaptor, (c) 1982.
The resulting RGB video signal is almost the same, quality-wise.
Inside the machine
Atari started the mod with a classic PAL Atari 800 as base (PAL computer with PAL OS), and added components. Please note that the regular video composite output (hidden here) is still present and still works, in parallel with the PERITEL output (see below).
Inside, you might spot an unusual "PTL" sticker; I assume that "PTL" stands for "PERITEL". Outside, in addition to the regular sticker with serial number, a hand-written sticker was also added with a PERITEL "PTL" specific serial number. I really wonder how many of these machines were made.
The PERITEL adaptor daughterboard-card
The RGB signal from this PERITEL adaptor
And now the strangest part. This high quality RGB signal in a PERITEL/SCART connector only displays 8 colours. In fact, it ignores the actual colour to display. It simply translates the luminosity of the original colour into a new colour, picked in a palette of 8.
Obviously, this yields to very strange colours in some games, although they remain "playable". It is also important to note that there is a noticeable delay in the PERITEL output. This is obvious with this "test setting" where the two signals are both displayed, side by side. The delay probably creates difficulties in game which are really time-critical.
A video expert got my attention about something weird in that "luminance" to "new colour" conversion.
If you are familiar with the very classic colour PAL/SECAM test card, you know of course that the colours were not selected randomly. In that specific order, these colours create a perfect gradient from white to black when displayed on a black and white tv set.
But look what happens here... Take a black to white gradient in the Atari (any dark to bright gradient of any colour will produce the same result). Now see how this gradient is converted into 8 solid colours for the signal sent to the PERITEL/SCART connector. And now look what happens when that signal is displayed on an actual black and white tv set.
You would expect the original black to white gradient to re-appear, right? Well, no, because the PAL test card uses this order:
White, yellow, aqua, green, pink, red, blue, black (The RGB colours componant are alternated as depicted below)
Whilst the signal generated for the PERITEL/SCART connector uses this order:
White, aqua, yellow, green, pink, blue, red, black
There must be a good reason for this, so I wonder why...
Running software (games!) on the two video outputs
On the large display (left): RGB signal from the PERITEL adaptor. On the small display (right): signal from regular Monitor (video composite) connector.
PERITEL Specific software
Since Atari considered from the start (*) that the 400 & 800 models were serious computers for learning – and not only excellent computers for gaming! –, they made the extra effort to create a specific version of existing educational programs especially for these PERITEL Atari 400 & 800. These programs are not merely a French translation. They feature different colours, a reworked palette. This update was needed because all the colours had to be reconsidered, and selected according to their luminosity. Later, other versions of these educational programs will be re-released in French for the XL computers, this time matching the original colours of the original tapes.
Please note that the colours selected for these alternative PERITEL versions are not picked in a black and white gradient, but other colours, selected purely for their luminosity. This can be confirmed if you run the software on a 400/800 PERITEL computer and compare the PERITEL and Monitor outputs. Alternatively, you can also run the software on a non-PERITEL computer (for instance a 800XL) and see for yourself that it features colours.
(*) The first cartridge, CXL4001, is "Educational System – Master cartridge". Then comes "Basic" (CXL4002), then "Assembler editor" (CXL4003), then the first game "Basketball" (CXL4004).
Last but not least, the PERITEL Atari 800 came with unusual power supplies, that provided 2x 9V AC at 1.7A + 1x 6V DC at 350mA.
Using 'PEEK' commands in BASIC to find out about the OS, Basic and GTIA versions.
For your information, the results are:
PEEK(53268) = 1 [PAL/SECAM]
PEEK(65528) = 214 [400/800 OS Rev. A/PAL, 1979-06 (common)]
PEEK(65527) = 255 [Not a XL/XE]
PEEK(43234) = 162 [Atari BASIC Rev. A, in external cartridge]