Gigatron Hackers

While I enjoy your enthusiasm, please follow forum etiquette and keep existing topics on-topic.

It's alway a bit easier to test on the highest bit. So I end up with this: 0200 2b 30 STW $30 |+0| 0202 59 00 LDI 0 |Y.| 0204 2b 32 STW $32 |+2| 0206 59 01 LDI 1 |Y.| 0208 2b 34 STW $34 |+4| 020a 21 30 LDW $30 |!0| 020c 35 53 13 BGE $0215 |5S.| 020f 21 32 LDW $32 |!2| 0211 fa 34 ORW $34 |.4| 0213 2b...

Finally, I assemble one xD xor_ttl.zip Congratulations, well done :-) prb.png so, code SYS_SpriteCopy_118 .LD [srcAddr],X ; src line 0 .LD [srcAddr + 1],Y .LD [Y,X] looks like X=peek(srcAddr] Y=peek(srcAddr+1] A=peek[y*256+X] ? Exactly.

This is the fastest and clearest way to evaluate an idea. Much better than just English, and very to the point. Thank you. Some quick feedback: 1. The block diagram doesn't make it clear to me what bus A and bus B are connected to, because they seem to be drawn as one. 2. IR3 is used in two instruct...

For those interested in software developments, our Apple-1 emulation now includes not just the Baum/Wozniak disassembler as published in DrDobbs, but also their famous mini-assembler back ported from Apple ][. With this you can enter MOS 6502 mnemonics on the Gigatron itself and execute them without...

I find I reset the ProMicro quite often where it seems to hang. The original BabelFish has an escape mechanism against hanging in case of a communication error. I found that this isn't present in the Reloaded version, as this got written in a different way. This may be a factor as well. (That is als...

One advantage of the ROM is the ability to add custom and specialized functions though. This can be an appealing option, but you are not going to eliminate chips to gain this advantage. Probably not. We also tried the Z80 approach but indeed it didn't save any chips. It only made it harder to under...

The idea comes up frequently enough that it is the Gigatron FAQ :-). In the 1970s, very big ROMs were either slow, and large arrays of fast small ones completely out of place. Large capacity and fast-enough ROMs that can take over an 8-bit ALU function or some other complex logic only came about in ...

for the SDC, it first gave a Vol.ID FFFF FAILED , and after some partitioning and formatting it errored out with Vol.ID 0000 FAILED ; Maybe it is related to the alignment of the partition? The one that worked had the LBA flag on and its first sector was at 2048. I'm testing with a 128K system. It m...

There is an interesting thing going on with the sequence for entering SPI mode on these devices: for some SD cards CMD0 seems to send its reply without driving the bus in both directions: as if those cards still only have a weak pull-up (or none) on the MISO line during that response. Our pull-down ...