SDX 4.20 EPROM

[+bf2k+]

I opened my SDX 4.20 cart today and it has a 27512 EEPROM in it. Is this size required for SDX 4.20 or would a 27128 work? And if so is it a direct plug-in replacement?

 

Edit: I want to put 4.22 in it.

Edited April 16, 2009 by bf2k+

[+Guitarman]

I put 4.22 in mine a while back. It will need the 27512 and it is a direct switch. It is 64Kx8bit=512K. I didn't like the FTE header in it so I edited the code and put ICD in mine. Just didn't seem right to see anything else there!! LOL

Edited April 16, 2009 by Guitarman

[kurtm]

I put 4.22 in mine a while back. It will need the 27512 and it is a direct switch. It is 64Kx8bit=512K. I didn't like the FTE header in it so I edited the code and put ICD in mine. Just didn't seem right to see anything else there!! LOL

 

Hmmm. That's not a bad idea

[flashjazzcat]

How does one go about putting the later versions of SDX on an EPROM in an original SDX cart?

[kurtm]

How does one go about putting the later versions of SDX on an EPROM in an original SDX cart?

 

When I did it, I erased the EPROM in the cartridge and put the new image on it. It wouldn't have been cost effective for ICD to make a run of masked ROMs at that point, so they just put them on EPROM.

[spookt]

Is there a good image of 4.22 floating around? I have a bunch of 27c512s here so I might give it a shot. What were the differences between 4.20 and 4.22 ?

[flashjazzcat]

How does one go about putting the later versions of SDX on an EPROM in an original SDX cart?

 

When I did it, I erased the EPROM in the cartridge and put the new image on it. It wouldn't have been cost effective for ICD to make a run of masked ROMs at that point, so they just put them on EPROM.

Presumably a special EPROM writer is necessary to accomplish this? It's either that, or even better fit SDX on the motherboard.

[mimo]

How does one go about putting the later versions of SDX on an EPROM in an original SDX cart?

 

When I did it, I erased the EPROM in the cartridge and put the new image on it. It wouldn't have been cost effective for ICD to make a run of masked ROMs at that point, so they just put them on EPROM.

Presumably a special EPROM writer is necessary to accomplish this? It's either that, or even better fit SDX on the motherboard.

yes, an eprom burner and a uv eraser to delete the old rom

[kurtm]

When I did it, I erased the EPROM in the cartridge and put the new image on it. It wouldn't have been cost effective for ICD to make a run of masked ROMs at that point, so they just put them on EPROM.

Presumably a special EPROM writer is necessary to accomplish this? It's either that, or even better fit SDX on the motherboard.

 

 

I guess I should have said I erased the EPROM *from* the cartridge. But yeah, you need an EPROM programmer. I just happen to have one. (At the time, had borrowed the same kind from a friend). I'll try and take some pics of my SDX cart.

[kurtm]

Is there a good image of 4.22 floating around? I have a bunch of 27c512s here so I might give it a shot. What were the differences between 4.20 and 4.22 ?

 

http://ftp.pigwa.net/stuff/collections/nir...CAR/SpartaDosX/

 

Not sure what all the differences are. One is the FTe branding. I thought there was supposed to be some y2k correction in the time code. Not 100% positive on that though.

[spookt]

Thanks. I never think of looking there

 

FJC - AFAIK you can only put the original ICD or FTe versions into an old cart by just flashing the ROM. If you want to get 4.42 in there MetalGuy posted up a thread a while back about how to accomplish it here. It's a bit of surgery so I think I may upgrade my 4.20 cart to 4.22 and then get hold of an AtariMax flash cart for 4.42.

 

If you want a EPROM burned with 4.22 let me know. I have a few sitting on my desk at the moment

[kurtm]

FJC - AFAIK you can only put the original ICD or FTe versions into an old cart by just flashing the ROM. If you want to get 4.42 in there MetalGuy posted up a thread a while back about how to accomplish it here. It's a bit of surgery so I think I may upgrade my 4.20 cart to 4.22 and then get hold of an AtariMax flash cart for 4.42.

 

Yeah. I guess with the subject of the topic, I didn't realize what flashjazzcat for, in terms of getting 4.42 in the original cart. Sorry.

[drac030]

Is there a good image of 4.22 floating around? I have a bunch of 27c512s here so I might give it a shot. What were the differences between 4.20 and 4.22 ?

 

One bugfix (but this was probably done already in 4.21), and ugly copyright message.

 

EDIT: and RAMDISK.SYS uses 65C816 block move instruction to transfer data, when the processor is detected. This is probably the most important change the FTe did.

Edited April 20, 2009 by drac030

[trub]

EDIT: and RAMDISK.SYS uses 65C816 block move instruction to transfer data, when the processor is detected. This is probably the most important change the FTe did.

DLT introduced the 816 block moves in 4.39, have you forgotten??

FTe's 4.22 just tries to detect 816 CPU (or Sweet16 board) and do nothing with it later.

[drac030]

DLT introduced the 816 block moves in 4.39, have you forgotten??

 

Yes, right. I just vaguely remembered that it was something with the 65C816 the FTe did with the ramdisk.sys. Real 65C816 support is indeed a much later.