Old drive options

[JKnightandKARR]

I have 3 options for replacement drives in old systems such as my 44-pin systems. Ordered 2 of them, will try em n see what happens!
1 is SATA to 44pin ide, just plugs right into the drive!
The next 2 are 2 different m.SATA to 44pin ide, will try them both n see what happens. Also got a 32 Gb m.SATA drive, will just partition on my desktop in advance in smaller sections in 2Gb or less.

[granz]

Interesting, I'll have to remember this in case I need to try options for hard drives.

Thanks, Joe.

[JKnightandKARR]

Interesting, I'll have to remember this in case I need to try options for hard drives.

Thanks, Joe.

Your welcome. I got the SATA to 44 pin IDE and the narrower m.SATA to 44 pin unit, which has the advantage of 3.3v or 5v drive selectiong via a switch, not sure on the other, with a drive, so Fingers crossed.

[JKnightandKARR]

Well, I got the SATA to 44pin IDE adaprter, and the m.SATA drive today, I tried the SATA adapter on the Z-Star EX, didn't power up, but gotta double check if I put the ext cable in backwards or something...

[JKnightandKARR]

The m.SATA adapter is here. I picked the smaller one due to it having a 3.3v n 5v selector switch, so will try that n see what happens, also noticed that m.SATA seams to be same as some WIFI adapters.... lol wonder if can locate dual drive 44pin ext cable n add WIFI to the Z-Star EX with some created drivers?

[Chris Savage]

gotta double check if I put the ext cable in backwards or something...

So, was it backward, or something else going on?

[JKnightandKARR]

gotta double check if I put the ext cable in backwards or something...

So, was it backward, or something else going on?

No idea on that one, but the other one m.SATA adapter DID show promiss!!! No screen, but unlike all others, the Z-Star DID inital beep! So fingers crossed!

[Chris Savage]

No idea on that one, but the other one m.SATA adapter DID show promiss!!! No screen, but unlike all others, the Z-Star DID inital beep! So fingers crossed!

<fingers crossed> 

[JKnightandKARR]

No idea on that one, but the other one m.SATA adapter DID show promiss!!! No screen, but unlike all others, the Z-Star DID inital beep! So fingers crossed!

<fingers crossed> 

If I knew hacking, I'd hack BIOS to make support easier...

[Chris Savage]

If I knew hacking, I'd hack BIOS to make support easier...

Ah, the good old days...hacking a wedge into the BIOS. Biggest trick was calculating a new checksum so that it wouldn't fail on startup. Easiest way was skip the ROM checksum. 

[JKnightandKARR]

Some photos of the m.SATA drive.





Edit: Think I need new website hosting or something.... I only see 2 of 4 images at the moment

[JKnightandKARR]

If I knew hacking, I'd hack BIOS to make support easier...

Ah, the good old days...hacking a wedge into the BIOS. Biggest trick was calculating a new checksum so that it wouldn't fail on startup. Easiest way was skip the ROM checksum. 

I'd try it if I knew how... I have a copy of the last BIOS for the Z-Star

[Chris Savage]

I'd try it if I knew how... I have a copy of the last BIOS for the Z-Star

Well, for starters, it was much easier back in the DOS days. Now we have UEFI BIOS and even the Plug & Play stuff was more than I wanted to mess with. But, back in the day (DOS), the BIOS was fairly simple and you needed to understand 808x / 80x86 assembly language and have a disassembler. You could actually use DEBUG to show blocks of memory and even write assembly code. Finally, it always helped to have a list of the INT calls for the PC BIOS.

Many things could be done by simply loading various registers and then calling an INT x. Now, if you were so inclined and / or motivated, you could create COM files that you could run from the command line. I created such simple programs back in the day. For example, I created a program called, "O.COM", which, when executed would flip the video refresh bit and then call an INT which would toggle video refresh. So it acted as a simple toggle screen saver. Typing "O" and hitting enter would either turn video on / off.

But, to what you're getting to, you could disassemble the entire BIOS and add / edit code, then recompile it and burn it onto an EPROM. On many systems you would get a ROM Checksum failure unless you either modified the code to ignore the compare or figured out what the checksum should be and updated that information before burning the EPROM.

It's been a long time, but IIRC there were 2 or 4 bytes that held the checksum. These bytes were zeroed and then updated with the checksum before burning the EPROM. The reason you had to do it this way is because when you updated those bytes, the checksum would no longer match that of the entire EPROM. Anyway, you could still do it with older systems. I made minor changes for specific purposes on a few very specific systems.