guus.assmann

Hello kimchipenguin, Is there any data / link / PDF and more. Is it possible to build this now? I'm intrested. BR/ Guus

Hello Tillek, Yes, You nailed it. I'll have to get another MegaST to test it, as it doesn't work in the one I've selected. I sure hope I can get it to work. Why have you not tried to fix the computer? The SST 68030 is the fastest card around and it matches the speed of a TT. Can support 12MB of Ram. And the manual is very nice to read. BR/ Guus

Hello, Does anyone know this card? What does it need to boot? e.g. Ram / type Tos on MB or not? Are there any programs for it? Any info is welcome. The card has a 68030, 68882 and 2 Eproms. And some slots for Ram. It fits a 68000 socket. After I plugged it into a working MegaST board, nothing happened. No boot (and no smoke) It was as it's shown in the picture. BR/ Guus

Hello hunter44102, Basically it's the same. The shorter screws go into the front of the machine. As not to stick up in the thin part of the cover. And the longet ones go th the plastic "poles" that go throught the interior. Should not be any problem. Just look to what the srew gets into and how thick that is. Also, round holes for things in the interior. And the "square" ones to hold the parts together. BR/ Guus

Hello Kyle22, Then it would not fit the 1200XL or 800XL/XE BR/ Guus

Hello Xebec, The signals on the serial side do look ok. RS232 is usually not damaged if connected wrong. It just doesn't work. But will if you reconnect. An output is mostly plus or minus 12V. An input between 3 and 8V, mostly plus. BR/ Guus

Looks nice and flat. It might work very well. However, consider insulating the shield.

The 7 or 8 bit refresh has to do with the memory chips. Older DRAM's use 7 bit refresh. The newer (and faster) ones had 8 bit refresh. So some memory upgrades to 256K needed an extra bit for the refresh. That was created using a counter. Have a look at the attached schematics. (a rework from the original design) So I assume that Atari was planning to use different memory chips and they would need another way of multiplexing. Hence, two different Fraddy-chips. BR/ Guus 256K.pdf

Hello DavidMil. Most of the above is not right. The difference is in the multiplexing for the DRAM chips. In the oldest Freddy chip, this uses is only 8 bits. And for the newer one it's 9 bit. If memory serves right. The same was with the Antic, that also has 2 versions, where one has 8 bit refresh-counter and the other one has 9 bit counter. So the newest Freddy would work in both machines, the older one just in the machine with the oldest (an probably slowest) Dram chips. BR/ Guus

Please have a look at the attached files. This is a PCB for the cartridge slot. And I've build it and checked if I could read the registers. That worked quite fine. The Uart is the same as on the blackbox. It would be better to decode the address a bit further, but that's about all. There's just no software, as I didn't want to spend the time for that. Although it shouldn't be too difficult, I've once written a RTC-clock driver and that worked just fine. BR/ Guus UART.zip

Hello Kyle22, Can you please explain what the use of the serial connection would be? What is it supposed to acheive? I'm trying to understand the significance of an endavour to create a fast serial device for the Atari. BR/

Hello Steve, You could consider a Flash-Rom as a more modern replacement. But is some casses the're not 100% compattible. The speed can be higher and that's not an advantage in all hardware. BR/ Guus

The thin pins do fit nicely in the socket on the bottom of the MegaSpeedy. And the tick parts fits well in the 1050 socket. However, if the thick pins have been in the 1050 socket, it may not connect to the 6507 processor is that needs to go back. Either way is ok, as long as you don't break any pins. BR/ Guus

Hello MacRorie, This sometimes happens to me as well. We humans are easilly distracted. :-) All data that I have available is the Zip that I've posted. I have used the 16F876A-I and that works just fine. No idea if the 18F242 is a possible replacement. The source code is in the data as well. Just look at the directory "Sources\firmware: Eiffel.asm" One challenge or disadvantage. All comment is in French language. And that's not so easy if it's not your native langage. Make sure you put both the program and the EEprom data in the processor. (I forgot about the EEprom and then it won't work) BR/ Guus

Hello MacRorie, 1) The schematics were done in Ulticap. This program is now part of Multisim. The .SCH file is the design. 2) The LCD is connected to the J1 connector. Yes it could have been smaller with an extra board. But I choose not to. 3) Coldfire is not needed. But at the time it looked intresting. I've not used it. Needs another processor as well. 4) The PS/2 connector is reused from a PC-MB. It's a green and purple one on top of eachother. That saved some board space. BR/ Guus

Hello Guys, Please find attached the complete information I have on the Eiffel inferface. It includes schematics and PCB designs. I've build at least one of the two PCB's. I cannot remember why I have two designs. Usually, the newest is the one I made. What I did, was make a copy of all relevant PDF's on a transparant film. Then glue the sheets together, with a piece of PCB in between as a guidance for the Photo-sensitive PCB. The design was made with Ultiboard. Now know as Multisim. BR/ Guus PCBS.zip

Hello Guilaume, Just now, I've checked the schematics for the TT. It uses the MC146818 clock chip. And an external clock generator, using a 4069 chip, U402. Only 2 gates A and B are used. Using this C-Mos chip gives a lower power consumption than having the MC146818 do the oscillator. (It can) The capacitor C408 is to be made adjustable. Crystal is Y400. BR/ Guus

It may very well be that it can be adjusted. On the much older MegaST, there's an adjustable capacitor. And the same on a MegaSTE. For these 2, I have a bare board and had a look. For the TT, I'm not sure. But it can very well be the case. (Check the schematics) If you can't find it, let me know and I'll try to invest some time to find out. And only if this fails, replace the Crystal. (Not 100% riskfree, adjustment = lower risk factor.) BR/ Guus

Could it be a /CS line to a memory chip that has to activate the SO input? I don't remember the Happy memory map. And on a Happy-clone with display, it could be the address of a display? BR/ Guus

Well, it does have a CPU attached to it. And it also looks like the wire won't just come off. Looks like some quality work. But curiuos as I am, I'd like to know how it works. And also, if it can be added to the MegaSpeedy. BR/ Guus

Hello all, In my opinion, the calculation ggn has made, applies to "controlled bit banging" Also, for serial communication, there's: Start-bit, data bits 7 or 8, parity and one or two stop bits. (just below 50% overhead) Most serial port periperals have a UART capability. This reduces the amount of processing power needed. The UART takes care of the timing and addition of the extra bits, also does "flow-controll". And often it has a buffer. So the CPU gets an interrupt once the byte is send or received. And there's also a 'Data overrun flag" For the 8-bit, the 850 modul did all of this work for the computer. And without the 850, the Pokey did part of the work, like a Uart would. So there's more to the story I think..... And it's not really possible to compare the systems, as the results are reached in completely different ways. BR/ Guus Assmann

Today I've successfully tested the HBS240 with an 68881 FPU. When using Gembench 3 or 4 the FPU is detected and I get the expected values for the calculations. So this confirmes that the GAL is ok. I've use a 7nS device. BR/ Guus Assmann

Hello DarkLord, Who's Jo Even Skarstein? Thanks to a tip from Frank Lukas, I did find the article. Next problem is, that there was a disk with the magazine. This disk contains a program to generate the content of an Eprom for a monitor timing generator. And now I do need the program...... All the rest is done or do-able. BR/ Guus Assmann

Hello, In the CT magazine of 1992, numbers 9 and 10, there was an article about the speedup of the MB. This was to 12Mhz. Does anyone have these articles and can they be made available? BR/ Guus Assmann

After a lot of setbacks, I finally managed to get a Jedec file. It's been made with Hatari emulator and the GABI software from Ralf Zimmermann. The GAL does give the correct reaction on my testboard. But in the HSB it doesn't work. I may have destroyed the 68881, it's been in the socket 90 degrees counter clockwise. Not sure if it can surrvive this. The Power Supply didn't start. With the chip seated properly, it still doesn't work, but the Supply starts correctly and the computer runs just fine. I hope I can find another 68881 or test it in another way. Guus DEC68881.zip