Search found 52 matches

by lb3361
Yesterday, 00:48
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 83
Views: 6327

Re: New vCPU instructions 2.0

Ideas for prefix2. I now have long and fp support in the C compiler. One of the issues is that code becomes very bulky because moving data around requires a lot of instructions. For instance moving a long between registers requires 2 ldw and 2 stw (8 bytes) and moving a float requires another 4 byte...
by lb3361
07 Jun 2021, 17:26
Forum: Hardware and software hacking
Topic: Video Repeater
Replies: 3
Views: 195

Re: Video Repeater

Hans61 wrote: 05 Jun 2021, 17:44 I'm not sure now, but doesn't the 128K expansion also need a defined state of the RAM banks and isn't this established via the ROM when booting?
One of the very first thing the Rom does is instruction ctrl(0x7c) which precisely resets the expansion into a safe state.
by lb3361
30 May 2021, 10:12
Forum: Hardware and software hacking
Topic: SYS_CopyMemory and SYS_CopyMemoryExt
Replies: 2
Views: 84

Re: SYS_CopyMemory and SYS_CopyMemoryExt

Done. Your dword routine might have comparable speed and lower startup costs. The maximal speed depends a lot on how many invocations fit in the 148 cycles of the typical runVCpu call. This is why I eventually went with bursts of 6 bytes. I could not fit two bursts of 8 bytes in 148 cycles. But two ...
by lb3361
30 May 2021, 04:38
Forum: Hardware and software hacking
Topic: SYS_CopyMemory and SYS_CopyMemoryExt
Replies: 2
Views: 84

SYS_CopyMemory and SYS_CopyMemoryExt

I wrote two useful native routines inspired by SYS_SetMemory_v2_54. SYS_CopyMemory copies a block of memory from one address to another. The main caveat is that you cannot cross page boundaries, which means that the size of the block must be less than 0x100-lo(srcAddr) and 0x100-lo(dstAddr). It can ...
by lb3361
29 May 2021, 21:12
Forum: Hardware and software hacking
Topic: Possible ways of speeding up the Gigatron
Replies: 32
Views: 1776

Re: Possible ways of speeding up the Gigatron

Time is an issue on my side too. And the Gigatron is an infinite time sink... Working on a C compiler for now...
by lb3361
29 May 2021, 13:53
Forum: Hardware and software hacking
Topic: Possible ways of speeding up the Gigatron
Replies: 32
Views: 1776

Re: Possible ways of speeding up the Gigatron

About finding a control bit. I am thinking about ways to get more control bits from the ctrl instruction. In my version of the extension board, I've repurposed spi3 and spi2, but I cannot say that I am happy with this solution. The good news is that changing this just requires reprogramming the gals...
by lb3361
23 May 2021, 11:46
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 83
Views: 6327

Re: New vCPU instructions 2.0

I also need to know the order of the operands. For instance, ORBI(x,y) is x the address aa and y the immediate II? Which one comes first in the encoding: 95 aa ii or 95 ii aa? Plus I need to test. This is why I prefer to wait for the rom source.
by lb3361
22 May 2021, 20:57
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 83
Views: 6327

Re: New vCPU instructions 2.0

I have about 10% reduction in code size, but I am only using a subset of the new instructions as I do not know their opcodes and I cannot test. I also read you have a number of interesting sys calls. I am hoping to use as many of them as possible, then maybe propose new ones. For instance, memcpy() ...
by lb3361
19 May 2021, 14:21
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 83
Views: 6327

Re: New vCPU instructions 2.0

See https://github.com/lb3361/gigatron-lcc for the work in progress on the c compiler.
Using -cpu=6 substantially reduces the gt1 file sizes despite only using a few of your additions. I was not able to test them though ;-)
by lb3361
19 May 2021, 13:55
Forum: Hardware and software hacking
Topic: Possible ways of speeding up the Gigatron
Replies: 32
Views: 1776

Re: Possible ways of speeding up the Gigatron

I am running 'WINCUPL' under Wine to prepare the JED files. Then I program them with minipro and a XGecu TL866II+. See the readme file at https://github.com/lb3361/gigatron-lb/tree/main/hardware/extension-retro As for more ambitious CPLDs, I considered using a XC9572XL for the memory expansion becau...