Kr0tki

Indeed, hue $3x in the default PAL palette is a bit too pink when compared to real hardware. I believe this is related to the issue described below. That's not strictly true. Adjusting Hue Step in Altirra does not change the hue of colours $1x, while it does on a real Atari; additionally, the real colour pot also modifies the resulting saturation of all colours. So Altirra's Hue Step is not equivalent to a PAL colour pot. I guess Altirra computes hue $1x directly from the "Hue start" setting and then uses it as a reference point of sorts for all other hues. In comparison, Atari800's "GTIA delay" setting replicates the behaviour of the colour pot accurately. Atari800 decodes PAL colours like a real TV would - its computes the phases of the colourburst as generated by GTIA in even and odd lines, then uses them to recreate the colour subcarrier's frequency and amplitude, and then uses the subcarrier as a reference to all other colours. As a result, the "GTIA delay" setting replicates the changes in colour hues and saturations of the real hardware. I have described the details in comments in Atari800 sources, in src/colours_pal.c.

It's called "colour pot", as in "potentiometer". And it is already implemented, see View->Adjust Colors->Hue step. On a related note, I've noticed a peculiar issue in the "Adjust Colors" dialog. Among the various reference colours listed in the bottom-right, there are these two entries: $AA: Pole Position sky $D8: Pole Position grass The problem is, "Pole Position" is among the handful of games that use different colours for NTSC and for PAL. So using these two colours as reference points may be somewhat confusing for PAL users 🙂

"XLFriend" from Quick Assembler uses Shift+Control+1, 2, 3 and 4. "E", a simple text editor published in Tajemnice Atari 4/91, uses Shift+Control+Esc, < and >. The OS allows to change key definitions via KEYDEF and FKDEF. I guess you could extend this to support Shift+Control combinations too, to allow the user to adjust them to their liking. Also remember that you can use console keys and Break in combination with other keys.

Maybe that representative was Technicallly Telling the Truth: it is a known fact that indeed, Atari was not shipping the chip in question (i.e. NTSC GTIA) to overseas markets.

I've found a reference in the "Archives Catalog of the Strong" in a collection of Atari Coin-Op Division materials. (This is only a catalog, the documents are in a library in Manhattan, if anyone wishes to research. 🙂) The collection contains documents referring to a "Moose Brain", "Mouse Brain" and "Mouth Brain" which may or may not be the same thing. I guess it was some widget developed by Atari for use in coin-ops.

😆

It was free only for the customers with a still-valid warranty. Others had to pay.

Oops, I misread the Field Service Manual. The procedure for testing the 2-port model, as described in there, differs from the 4-port one in that it specifically not uses the loopback board and omits the Port Test. Sorry for the confusion.

What was this 800 Black Box system? I understand it was an Atari 800 with some modifications, but finding anything on the web is difficult because of the unrelated "Black Box" hard disk interface. Dit it contain a special OS ROM? Did it support standard 5200 controllers, with their 2nd button and keyboards? The latter would require some rewiring of the GTIA outputs to make them work like on a 5200. I guess I could look into it, but it would be much less time wasted If I had access to the source code. Interesting. Are there any other occurrences of ZZZROM in the sources? Wait a moment, so Atari planned to connect a Votrax to the 5200's expansion port?

Interesting! I would assume that the 2.3 diag cart, being a later version, would correctly support all 5200 models released up to that point, not only the latest one. Especially considering that, according to the Field Service Manual, the 1.1 cartridge supports both the 4-port and 2-port models.

It's 4B58 0000 for the C019156 OS (the original one) and 54E4 0000 for C019156A (the "2-port" BIOS). Where does the 1.1 number come from? What other 4-port OS? There were only two OS versions.

Sorry, it's just not my cup of tea.

Well I don't know why they don't work, because I haven't seen them, but still, I don't see the point in investigating the issue, if the 16 KB ROMs work for you.

Why can't you just use the 16 KB ROM image?

Your numbers don't seem to be correct. In the Atari Engineering Information System Item Master List, the parts are listed as: C010177 CRYSTAL: 3.579575 MHZ C016010 CRYSTAL: 3.579545 C061090 CRYSTAL,3.579545 MHX,QUARTZ and the frequencies are the same in Field Service Manuals for the various computer and console models. So there is apparently no difference in frequencies between the two.