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Author Topic: BLU Serial Bootstrapping?  (Read 3318 times)

blusnowkitty

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BLU Serial Bootstrapping?
« on: April 24, 2020, 11:40:30 pm »

Just curious more than anything - I've been playing around with trying to get BLU to boot on my Lisa despite the slightly damaged I/O board. It seems serial communications are fine as I can send the BLU RS-232 payload without issues and the bytes the manual says to check always send correctly. However whenever I try to run the BLU payload I get Error 48 - Illegal Instruction from the Lisa ROM. This happens in both ROM F and H.

What I'm not 100% sure I'm doing correctly is using the right serial terminal program. I'm using an old Windows XP box with HyperTerminal configured as 57600 8,N,1 with flow control set to Hardware.. The BLU manual says to send it as either binary or plaintext; HyperTerminal in Windows XP only lets me send as Kermit, ZModem, XModem or Plain Text so I choose the plain text option, but as mentioned previously every time I try to run it I only get greeted with Error 48. Is HyperTerminal to blame? Should I use a different terminal emulator? I have Macs and PCs of all ages running everything from pure DOS to Windows 10, System 1.1 to macOS Catalina, and even some Linux boxes for good measure. Or is this likely just an issue with my I/O board and I should just wait until the new one comes in?
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stepleton

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Re: BLU Serial Bootstrapping?
« Reply #1 on: April 25, 2020, 07:16:05 am »

Seems like you're checking all of the obvious things, including the dreaded CR->CRLF conversion that the BLU manual warns about. As you suggest, I would try a different terminal emulator as my next step. (Also, is software flow control turned off? I don't expect it should matter, but it shouldn't be on...)

If that doesn't work, I might investigate the loaded data in Service Mode some more and see if anything looks suspicious. Maybe the first few hundred bytes are OK, but then the later ones become all zeros or something like that? The BLU manual says that the loader loads 53762 bytes, so addresses that do have loaded data should be $9C0 through $DBC2 I suppose.

If this investigation is inconclusive, you might try creating a binary file of 53762 bytes with different contents, perhaps an easily-recognisable pattern, and seeing if parts of that pattern are reproduced faithfully on inspection in Service Mode.

Note that the BLU manual's bootstrapping section also has instructions for selecting slower data rates by modifying the type-in Simple Serial Loader program---maybe one of these will result in a more reliable transfer?


Ah... fond memories of bootstapping BLU back in 2012, before I did the pad replacements for my Lisa keyboards. I wound up "typing" in the loader on the bare PCB with a "stylus"---that is, one of the few remaining good pads taped to the end of a pencil!
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blusnowkitty

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Re: BLU Serial Bootstrapping?
« Reply #2 on: April 25, 2020, 01:49:27 pm »

As I thought, it turns out HyperTerminal was the issue - just wanted to check and see if anyone else had run into the same issue, so thanks! Maybe let the official word be that if you're on Windows, don't dig out HyperTerminal?

I ended up downloading a terminal emulator called Yet Another Terminal - https://sourceforge.net/projects/y-a-terminal/files/ - and it seems to work for what I need. It has a pure Binary transfer mode and I also made sure to uncheck the line break option. Not sure if that made any difference but it sent the BLU serial payload over and my Lisa ran BLU just fine.

For what it's worth, my 2/5 is officially a cobbled-together system. The chassis has Applenet #3134 but the CPU board is #5817. Probably explains why only the I/O board suffered corrosion damage and all the other boards inside are in pristine shape. Playing around with the floppy diagnostics and I think it's a miracle that the Lisa can even read the I/O ROM during POST - BLU can't and every floppy operation I tried ended up in a crash or some random error.
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