Recent content by Bruce Tomlin

This is what Svenska was talking about. They are "tokens", but they don't need to be in the same symbol table with labels. When you get the next token from the line, the "get word" or whatever gets a whole chunk of alphanumeric characters, or just a single character, and returns a type of...

A test suite could be as simple as a few .asm files and .hex files generated from them. You then manually run a script that runs the current version and compares that it produces the same .hex files. In some ways it can be a rather leaky test, but you're still testing something, so it makes sure...

As far as I know, the only known software for this is unit in the "Petebug" thread, along with some attempt to reverse engineer it... https://forum.vcfed.org/index.php?threads/stunning-motorola-68000-system-made-by-computer-system-associates-usa-circa-1984.57947/ The other thread has better...

I don't know why I never noticed that LD SP,0600 in the reset button NMI handler. I've certainly had years to get familiar with the contents of that ROM. Anyhow, it's pointless because unless something interrupts it, nothing will use the stack until it can be loaded again, either by rebooting to...

Basically the main point of an ICE is to have control of the hardware that contains the CPU. It lets you test the real hardware with a real CPU that you can control manually, sort of like a front panel but more complicated. These days modern CPUs have built-in debugging support because signal...

It's really personal preference, though I can't ever recall CP A being used for that purpose, only OR A and AND A.

Nope, you can only LD (DE),A / LD A,(DE). I still don't know why it wouldn't let you do that. It might not do division. This is why I prefer to just use my own assembler and copy the result over. Yep, it's looking like it might not support much in the way of math. In a modern assembler you...

If you only want to do specific constant offsets, rather than computed offsets, you can LD IX,BODYX and use (IX+nn) with a one-byte offset. I'm pretty sure that's a positive (0-255) offset only. Another way could be: LD HL,BODYX LD D,0 LD E,A ; if the offset was in A rather than E ADD HL,DE ...

Yes, most keyboards these days are total junk. The worst in my opinion, more because of the deception than their mechanisms, are the ones that try to look like "gamer" keyboards, but are still mushy rubber domes underneath. I regularly visit the nearby by-the-pound Goodwill, so I get to see (and...

This. If you are going to use it yourself, then make it work the way you want it to work. But it's still helpful to have experience with different assemblers so that you can know what kind of things are possible. Macros is one area with a very wide variability, and it can be very tricky to make...

Yeah, that looks like someone did something stupid and bodged over it. Probably first broke the pin, then made a complete mess trying to solder a random bit of wire to the socket, which isn't even close to a sensible solution. I'd replace the socket too, and I'd try to start by just pulling off...

For what it's worth, what I'm really interested in is any 68000 version of MS-BASIC that I don't have. (I already have the Tandy 6000 decimal math, and the Macintosh versions). After finding a github stash full of IMD images, I'm not so sure that Tandy ever had the binary version. I'm kind of...

Having been there over 20 years ago, I can tell you that basically no "undocumented" 6809 instructions are useful. As mentioned above, there were some cases of redundant addressing modes that just took more clock cycles, but there are only two worthy of note. First is the TEST (aka HCF)...

I'll bet it's a MICROD CB-9201. https://manualzz.com/doc/9041785/microd-pcb--new-processor-card-cb9201-6

I've been taking some time the past few days to write a parser for .IMD images*, and that is correct, 26-6105 appears to only contain Model II Basic. It is 26-6457 that contains the decimal math Model 16 Basic 1.02.00 (* I refuse to run DOS crap just to extract stuff from those, and .IMD seems...