Activity

foft's activity

From 08/21/2017 to 09/19/2017

FO 07:29 PM EclaireXL Developer: RE: Accessing new Antic modes through BASIC?: Haha, fair point:) foft

FO 02:01 PM EclaireXL Developer: RE: Accessing new Antic modes through BASIC?: This is why I didn't prioritise it, no-one seemed keen to use it... Anyway its on the list and I'll get around to it after the big cpu/firmware rework. foft
FO 02:00 PM EclaireXL Feature #55: Replace main CPU: Still on step(i) but progressing well! foft

FO 01:14 PM EclaireXL Developer: RE: Register differences vs the original: I propose using the same bit of Sophia for hi-res mode colour too:
bit4 PMCTL controls additional color in hi-res mode.

0 - 1 color, 2 luminances (default)
1 - 2 colors foft

FO 05:39 PM EclaireXL Developer: RE: Images from VCFMW12: Thanks, exciting to see it on-display at a show. foft
FO 05:29 PM EclaireXL Developer: RE: Accessing new Antic modes through BASIC?: Actually I agree it would be cool.
So, if I fix the hardware, any hands up for an E: driver? So we can run existing software in 80 col mode with 4.5 colours?
foft

FO 09:24 PM EclaireXL Feature #55: Replace main CPU: I read up on the 'altera virtual jtag' and think I now understand how to get this connected, at least in theory.
I guess next steps that might make sense are:
i) Build a core with virtual jtag and signal tap and try to send it equiv... foft
FO 08:41 PM EclaireXL Developer: RE: Accessing new Antic modes through BASIC?: I can, but it doesn't work properly yet!
The register is 559, the shadow for DMACTL.
Normally its poke 559,0 to turn the screen off and poke 559,34 to turn it on. Which is the sum of 2 (normal width) and 32 (playfield dma on).
... foft

FO 10:06 PM EclaireXL Feature #55: Replace main CPU: Been trying out openocd locally with the cpu running in verilator. gdb connects, code loads and runs. Pretty cool! OK I just ran some commands as documented but I'm still pleased:-)
I'm very impressed with this riscv cpu project - see... foft

FO 09:39 PM EclaireXL Bug #59: Game test: Crownland: It requires 128K, can you check what memory settings you have? I can only reproduce without extended ram. foft
FO 07:44 PM EclaireXL Bug #59: Game test: Crownland: I'll have to check, I thought that worked.
BTW this one is better than v14: svideo_gtia9.sof foft
FO 07:43 PM EclaireXL Feature #55: Replace main CPU: The author of the cpu kindly got back to me with some details.
The wishbone interface adaptor looks pretty easy.
Apparently the chip uses a non-standard debugging interface though. Which is good actually since its simpler. However ... foft

FO 09:44 PM EclaireXL Feature #55: Replace main CPU: I've managed to get the spinal HDL project compiled, so now have a verilog or vhdl file for the CPU. It seems to have 3 ports. Instruction master, data master and debug slave. So I will need to map them into wishbone. They are also in th... foft

FO 01:40 PM EclaireXL Feature #55: Replace main CPU: To Panos' comment. Yeah I'd love some help, if someone could help me define the memory map and write the firmware for the RISC V that would be an enormous help. There are also many HDL parts that need doing if anyone fancies working on t... foft
FO 01:37 PM EclaireXL Feature #55: Replace main CPU: There are several problems with the current setup:
* The firmware is constrained by the current ZPU setup. Its hard to debug and tricky to add more memory to it.
* I'm struggling to meet timing requirements, due to the over-complex int... foft

FO 09:06 PM EclaireXL Feature #55: Replace main CPU: So I'm now thinking about ditching my address decoder rework and doing something more fundamental.
Using this CPU to build a complete system with a large linear address space. With SDRAM, block ram, custom chips, pbi and the 'zpu regs... foft

FO 09:18 AM EclaireXL Developer: RE: Curious if progress is being made on this project any longer?: Not much. Had some back issues after my holidays and generally not been very motivated with this project recently. It was always unlikely to develop at the same pace as when the new boards were made though, that was pretty unsustainable ... foft

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