guus.assmann

Hello, These caps have been put there so the computer would meet the FCC rules. But that doesn't mean by defintion that they cannot be removed. However in some cases it might increase the level of interference. Just see as you go along. BR/ Guus

Hello, Not sure if it's usefull. Please find what I've got that's labeled Kyan. The physical disk is also available. However, I've tested neither disk or ATR recently. BR/ Guus Assmann Kyan Pascal_B60 a.ATR

Hello Mq. , Digging into memory now.... The 7474 needed to be an LS type in my design. And also the 74LS02 was needed. I did test with S and F types, but that was no good. So the total timing is quite sensitive. The LS02 is most critical. For me, it was good that I had the IC's in DIL. That means using sockets. About 65C816, see the link to Berhard Pahl's site. There you can read what to do to get the 816 working. And yes, I tested it a long time ago. BR/ Guus

Hello Sikor, New PCB is better, I agree. But my desgn was from 1987. And the PCB is single sided. It also contains an extra 6520 to accomodate a printer port and RTC. BR/ Guus Assmann

Hello, Have done this many years ago and developed a PCB. It has also been published in the Dutch Atari magazine. (SAG) Yes, a 65C816 will also work, just a few minor changes to some pins. I do still have a PCB layout, in PDF format. BR/ Guus Assmann 65C02.zip

Hello, As more often, Google is your friend: http://www.atarimania.com/utility-atari-st-pc-speed_23201.html I searched for "Atari ST PCSpeed and it was the first hit.... DRDos worked very well on this emulator. And there's a 386 version, called "AT Once" in both an ST and MegaSTE version. BR/ Guus Assmann

Hello, This is indeed a PC speed. It was faster than the original PC, because the Atari did the I/O and screen. It's very much compatible with a PC. Made by Sack. Needs a disk to drive it and of course a Dos3.0 or so. Later, a 286 and I think also a 386 were made. BR/ Guus PC Ditto was a software emulator. Supercharger is a PC connected to the Atari with the DMA.

Hello Alfred, Maybe I've missed something? Why would we need another disk format? The 8-bit Atari computer is working just fine right now. What would be the benefit? Or maybe in other words: Do we need it or is it just because we can? BR/ Guus

Hello, Well, I've once made it. The idea was to have a solid state disk-drive. So I've made a bank-switched set of Eproms, copied Dos to Ram, initialised it and had it read the "files" in Eprom as if it were on a disk. I've never finished it, due to lack of time. And as things go, someone was interested and "promised" to finish it. That's the last I ever heard of it. Many yeas later I've made the Mega Speedy. (after taking it from the initial designer and with a lot of valuable help from Hias) This contains the Speedy units with a Dos build in. (and copy program) BR/ Guus

Hello Nezgar, What I mean is that erasing may destroy an Eprom if the pins are insulated from each other. So put the Eprom in a piece of conducting foam. Alternatively, put some aluminum foil over a pieces of foam and stick the Eprom-pins in that. Either way, the pins are electrically connected. Cause: During discharge you put energy in the chip. (Light = energy) Thus there can be (too larges) voltage differences inside the chip. And that can be destructive. I found this out when Eproms like the 2708 were about $150 a piece. (My boss was happy about this) Modern Eproms are less sensitive, but still.... BR/ Guus

Hallo, Also very important for erasing Eproms, make sure the pins are all electrically connected. If not, the Eprom may be destroyed and this show in failure to program. It will show erased but won't accept any programming. BR/ Guus

Hello, Sounds more like a short somewhere "further down the line" I'dd suggest to remove the output leg of Q8 and measure if the 12V is there. I guess it will be. Next, chech if there are any other (small) capacitors and their condition. Also, the transistor for the drive motor could be defective. BR/ Guus

Hello, You do need to tie the /Halt line high with a Pull-up. And the R/w is on a different pin. For the rest, the Sally-CPU will work fine in an old 800 board. (I've used it in various other boards) Also, it's not a big problem to buy a 6502. And a 65C02 is also available. Just compare the schematics to find out the pin numbers.

Maybe the thing you need to use is a Steinberg Midex Expander. This has 4 Midi-out ports and 2 inputs. Also an SMPT-in/out and 4 slots for dongle-keys. Due to 4 pieces 6850 Uarts, it can handle some nice high speed and not much lag. BR/ Guus

Hello Spanner, You cannot use a DC power supply. The 1050 needs 12V DC as well. This is done by a voltage doubler, also containing a capacitor. That part will not work with DC. Maybe the transformer can be repaired. It has a fuse inside, consisting of two pieces of wire, soldered together with some low temp solder. Replace this one. Or resolder it, using only flux and a clean soldering iron-tip. BR/ Guus

The above modification will just increase the speed of the serial port. And it has nothing to do with Midi. Also, reliability will not improve. It may be so that the serial speed of the Uart cannot be met by the program that needs to handle it. BR/ Guus

Hello Larry, Check the settings of the configuration register. There must be someting wrong there. Some programmers need a special command or menu to set the configs. I think the $400 is an Eeprom part, not sure if it's in use. BR/ Guus

Back to the topic. The capacitors are there to make sure the computer complies with FCC rules. For static, they don't do much. They will limit the communication speed as it takes time to charge and discharge them. If you use correct and shielded cables and make sure the connected devices are shielded. It's no real problem to remove them. And in reality, you won't get into any truoble if you remove them. BR/ Guus

Hello, I'm looking for the data sheet for a controll circuit on an Epson floppy unit. The number is SF9200-K or SF9200-CK. It's an 80 pin QFP ic and it's on the SMD 300 floppy unit. Can't find it with google. BR/ Guus

Hello PeBo, Start by opening the unit up. And see if it's dusty inside. Any dust is like a blanket, preventing the parts to cool down. Sometimes it is really simple, don't assume the worst please. :-) BR/ Guus

Hello fsmith2003, Yes, it could be a power supply issue. In that case, replacing some caps will do just very nice. And it's no "high tech" soldering. Look on the site of EXXOS to get some info or parts. BR/ Guus

Hello Bikerbob, Yes, only difference is symbols. And any keyboard will work, just maybe give an unexpected character on the screen.... BR/ Guus

Hello DavidMil, If memory serves right, the originals are rated 1Mhz. So the A-types should be just fine. Also, it will not do immediate harm if you would overclock the chips. They might get quite warm is a while, so that's what you should look out for. BR/ Guus Assmann

Hello kimchipenguin, Is there a link or can you post the PDF's? I cannot find it in the archives of the magazines. BR/ Guus Assmann

Hello kimchipenguin, As it happens, I'm an electronics expert. And also, I don't need Google to understand German. I'm so lucky that I have managed to learn the language quite well. BR/ Guus Assmann