General Category > LisaList2
Monitor format for ProFiles
pablo_marx:
--- Quote from: sigma7 on April 15, 2025, 01:25:24 pm ---
--- Quote ---tried each IO ROM
--- End quote ---
For IRL hardware, the I/O Board ROM is used exclusively by the Floppy Disk Controller's 6504... the 68000 can't even access it.
So the IO ROM version shouldn't have any affect on COPS/KeyBoard/Parallel/Serial/Sound etc.
--- End quote ---
The 68000 can certainly make inquiries of it, as it displays the I/O ROM version in the top right during boot/diagnostics. So it seemed feasible, but certainly very unlikely, given the error report that some piece of code could be checking the version and altering behavior based on the value (e.g. enabling some quirks mode code path when dealing with the COP), resulting in the behavior described.
Lisa2:
--- Quote from: pablo_marx on April 15, 2025, 08:56:10 pm ---
--- Quote from: sigma7 on April 15, 2025, 01:25:24 pm ---
--- Quote ---tried each IO ROM
--- End quote ---
For IRL hardware, the I/O Board ROM is used exclusively by the Floppy Disk Controller's 6504... the 68000 can't even access it.
So the IO ROM version shouldn't have any affect on COPS/KeyBoard/Parallel/Serial/Sound etc.
--- End quote ---
The 68000 can certainly make inquiries of it, as it displays the I/O ROM version in the top right during boot/diagnostics.
--- End quote ---
NO, this is not correct, the 68000 cannot access the IO ROM directly as James said. What happens is that the IO ROM version is written into the shared RAM by the 6504, and the 68000 reads that. Try it, If you were to remove the 6504 from your IO board and POST the system IO ROM displayed will be gibberish.
sigma7:
--- Quote ---
--- Quote ---the IO ROM version shouldn't have any affect on COPS/KeyBoard/Parallel/Serial/Sound etc.
--- End quote ---
... some piece of code could be checking the version and altering behavior
--- End quote ---
Fair enough... the 68k may certainly behave differently due to what the 6504 communicates (and thus influenced by the IO ROM)... but ordinarily it does not (with a couple of exceptions*).
The intent of my post was to avoid someone having the impression that eg. if their keyboard didn't work IRL (In a Real Lisa™) then the IO ROM might be a likely suspect. The IO ROM doesn't directly control operation of the I/O Board beyond the FDC.
* some exceptions being:
- The "Startup From" menu will show two floppy drives for A8, and one floppy drive for 88 -- further edit... I'm thinking this is more complicated... maybe two floppies appearing requires earlier revision CPU ROMs too?
- Xenix assumes the parallel port hard drive is 5MB or 10MB depending on A8/88
- The hard disk icon in the Startup From menu and environments such as MacWorks changes between a ProFile and a Widget
- The clock speed of the 6522 VIAs is different (approx. 500KHz vs 1.25 MHz), 88 indicating the 2/10 I/O Board designated as having "fast timers" per the source code comments, requiring different time constants.
edit: exceptions
stepleton:
--- Quote from: pablo_marx on April 12, 2025, 05:15:24 pm ---However when I use the connector menu to switch to serial port B and type a character into lisaem's adapter, there is an endless slew of Xmit Interrupt condition 61 errors and then lisaem crashes. So we may have another one for the lisaem issue list...
--- End quote ---
Finally getting around to trying out some of these images. For starters, this experiment with TERM.OBJ was successful in sending data in both directions on both serial ports.
https://photos.app.goo.gl/LVvA6mp1T7WfsjR68
TorZidan:
--- Quote from: sigma7 on April 15, 2025, 10:22:28 pm ---[The "Startup From" menu will show two floppy drives for A8, and one floppy drive for 88 -- further edit... I'm thinking this is more complicated... maybe two floppies appearing requires earlier revision CPU ROMs too
--- End quote ---
We are quite off topic, but I want to put this to bed:
I tried quite a lot of combinations of cpu and i/o roms in LisaEm. Here is how it works:
For "H" and "3A" cpu roms: The CPU rom checks the I/O rom version, and, based on that, shows different icons on the startup screen. It will show two floppy drives (and a ProFile) only if the I/O rom is "40".
All earlier cpu roms (I tried B,C and D) always show two floppy drives on the screen (and a ProFile), regardless of the I/O rom version; so it seems that they predate the Lisa 2 and XL.
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