PacMan

You need a video amp with low output impedance to drive the video input. That'll make it look better. /P

Put me up for two of those. /P

Which brings up a question that's really been bugging me. Does the 6502 downshift even for accesses like reading the Joystick Position, or is the lower clocking only triggered when you write to the TIA's ports? I've been crossing my fingers that it's the latter, because the former would make the chip incredibly erratic; but I'm concerned that I may just be practicing wishful thinking. The clock is always shifted down when when accessing the TIA and RIOT. I noticed that when implementing the RMT player on my 7800 using the XBoard and found that the POKEY was shifting the entire song down in pitch when holding a button down (= my stupid program). It went away with some clever programming /P

Just placed my order and I hope I got everything right. My German sucks big time so I did not get much of the terms for the delivery /P

They could have very easy. Do you see how much of the board is taken up by un-needed grounding spots? About 10% of the board. I wouldn't go so far as to call them un-needed but yes, the ground traces could easily have been reduced and a POKEY could have been fitted on the board with some clever placing and routing. /P

Yes, we can be 100% sure that this will not work. Even if you get the clocks 100% synchronized (Which you never ever will) you will have bus conflicts. These conflicts will affect the operation of both machines. You need to separate the busses completely. I don't see the point of trying this out. Instead, slap a FIFO on the personality module so that the processors can talk together. Then again I don't see the point in doing that either. Skip the initial steps and work on a draft on what you are aiming at and let us have a look at that. That should give us something to really discuss. The 244 is a buffer and the 258's are muxes. /P

I guess I'm just thick here. Could you wip together a simple block diagram on what you are after. Connecting two 400's with one memory bank just doesn't seem doable to me. /P

What you're looking for to get this working is a Multi Port RAM. These come in dual port configurations which would work nicely in this situation. Follow this link for more information. This would effectively open up a common RAM area between the two (or more) processors. Other solutions to multiprocessor problems is to have dual port FIFO's to exchange data. These are more suited for message based communication though. You could for instance create a support FPGA running a 6502 CPU on say 50 MHz connected with a FIFO to the main Atari system. This solution could even be included in a cartridge. /P

Addictive game. Uggly fonts but really addictive game. Thanks a lot. /P

True, if I want to work with something "hotter" than the Atari's I play with my GP2X. But this is probably because I'm more into software than hardware. However for mr Coffee Unix (I wonder if he has a Porsche 928 ) with a hardware background I can see that what he is discussing would pose a challenge. I will follow any progress mr Coffee makes with great interest and offer my input if I can. /P

drac030->Definitly ages !, I signed an NDA with WDC spring 2003 for their Terbium technology but I have not seen much from them since so it'll be interesting to see what they finally release. /P

I'm not sure what you are after here ? Why do you want to integrate an atari into an fpga ? Your estimate of hacking it together in 3 months seems a little aggresive. I do this for a living and know that 3 months doesn't by you much these days. Maybe if you had a few people working full time. Wouldn't it be easier to take a one-chip ARM-9 and port a scaled down version of win800 or similar. I started implementing the A800 in VHDL about 6 months ago and have managed to get about 50% of it working. I have designed it only from the available manuals and by running existing software (games mostly) to verify that the function blocks works. To verify 100% compatability I have then hooked a logic analyser to an old 800XL motherboard and compared the waveforms. This is actually what takes time... test and verification (as in any project). But I totally agree with you, the 800 was by far the system that gave me the most pleasure, and it still does. /P

Ehr, say what ?

I am pretty sure I have AMAC in the box. If the manual isn't to large, I will try to scan it, if you would like. Edit: I have the disk based version of Atari Macro Assembler which also includes the Atari Program Text Editor. There are books for both in the package. I will try to scan them for you. Oh, would you ! That would be great, I just need the commands for the editor and possibly the assembler options. I seem to recall that the editor could take a configuration file, an explanation on that would be superb. /P

Thanks a million, Do you also know of any documentation for medit (APX Atari Program-Text Editor) ?? /P

Hi all, I just decided to start using my XE computer to start writing software again and wanted to use the AMAC package. Does anyone know where I can get the manual for it ? /P

Thanks guys, Yes I believe they are available at Best but I prefer to have a (much) smaller switched unit + they are less expensive than the original parts. /P

Can someone please tell me the rating of a 800XL/130XE power supply. I'm in the process of building a few since the computer I just purchased didn't have one single supply with the /P

I'm looking for a few powersupplies for my 800XL's and 65XE. Does anyone have one that they would like to part with ??? /PacMan

Got mine yesterday and they look good. It'll be fun to install them and start playing around. /P

Retested on my old 6502 board computer and you are of course correct. It helps to connect all relevant signals that you want to measure on /P

Så vad gör alla ? Min Ataribakgrund är att jag köpte min första A800 1982 med 2 st 810 diskdrivar och utvecklade en hel del spel med. På senare dagar så har mitt Atari-intresse blossat upp igen. I takt med att spelkonsoler och datorer blir mer och mer komplexa så blir det tuffare och tuffare att orka med att driva egna pulprojekt. Men på mina Atarihäckar så är det mycket enklare och mycket roligare att skriva små applikationer och spel och göra roliga expansionsenheter etc. Mer info om mig och mina burkar finns i länken i signaturen. Vore kul och höra vad andra håller på med också. /Pacman

Finally got a complete system together and operating. Currently I am using the NoIce debugger (NoIce) to download code and debug with. So far most operations seem to work although NoIce seem to freeze up completely from time to time. Will try to post some pictures next time I get around to play with the system. /P

Well that certainly explains it.... eh..sorta The old Synertek 6502 did not show this behaviour.... I will check it again, gotta make sure I didn't miss something there. Very good document, thanks for the link. /P

I have been working on my RAMCart lately and found a strange behaviour with Sally. After doing the lockup sequence for the FLASH memory I used the instruction sta (Address),Y to store the data and start the write cycle. Now since I'm writing this post this obviously didn't work and I spent a good 4 hours trying to figure out what was going on. I finally brought out the good old logic analyzer to see what I was doing wrong. I found that the first unlock write cycles were good but the sta (Address),Y was actually performing a read cycle before the write, which screwed the FLASH write sequence up. Just to do a quick test I changed the instruction to sta (Address,X) and kabang, it works. Anyone seen this before ? I tested the exact same sequence on a system with an old Synertek 6502 which worked as expected. This is the code I used, that did not work: FlashByteWrite: sty Work_2 ; Store Y reg stx Work_3 ldy #$00 ldx #$aa ; Command sequence for unlocking the stx $8555 ; FLASH memory for writing or erasing. ldx #$55 stx $82aa ldx #$a0 ; Program command stx $8555 sta (Param1),Y; Store it to the flash jsr FlashWait ; Wait for the write to complete ; No error detection here, done in calling layer inc Param1 bne FlashByteWrite01 inc Param1+1 FlashByteWrite01: ldy Work_2 ; Restore Y reg ldx Work_3 rts This works: FlashByteWrite: sty Work_2 ; Store Y reg stx Work_3 ldx #$00 ldy #$aa ; Command sequence for unlocking the sty $8555 ; FLASH memory for writing or erasing. ldy #$55 sty $82aa ldy #$a0 ; Program command sty $8555 sta (Param1,X); Store it to the flash jsr FlashWait ; Wait for the write to complete ; No error detection here, done in calling layer inc Param1 bne FlashByteWrite01 inc Param1+1 FlashByteWrite01: ldy Work_2 ; Restore Y reg ldx Work_3 rts