Search found 6698 matches

by hoglet
Thu Jan 18, 2018 10:59 pm
Forum: hardware
Topic: Fault finding index
Replies: 86
Views: 16899

Re: Fault finding index

Hoglet, sorry, I need to go back and read that thread, but does you software check reads from memory with "known" values to spot dodgy RAM etc? No, unfortunately it doesn't do this automatically. In this case I did a "diff" against a known good trace, and because the error was e...
by hoglet
Thu Jan 18, 2018 5:44 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 52
Views: 1197

Re: SpectROM - Speccy emulator for the Pi co-pro

Rob, Is there any possibility you could save a sample screen of a game running on the emulator? i.e. literally just somehow pause the emulator and save the contents of the screen memory to a file. I'd like to add the Speccy attribute mode to the BeebFpga VideoNuLA implementation, and it would really...
by hoglet
Thu Jan 18, 2018 4:27 pm
Forum: hardware
Topic: Fault finding index
Replies: 86
Views: 16899

Re: Fault finding index

I don't know if this was the one Hoglet was using but he had been experimenting with a logic analyser based on a very cheap piece of hardware to actually sample the signals with the decoding and display done by open source software on the PC including writing a module to trace/disassemble 6502 inst...
by hoglet
Thu Jan 18, 2018 7:37 am
Forum: other vintage computer hardware, software and games
Topic: Reading EPROMS
Replies: 10
Views: 232

Re: Reading EPROMS

Are you planning to use any kind of level shifters?

If not, you could possibly damage the Pi, all of it's GPIO pins work with 3.3V levels.

Dave
by hoglet
Wed Jan 17, 2018 8:42 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 39
Views: 1012

Re: My New Acorn Atom :)

Please do post a video of this. It does sound quite strange.
by hoglet
Tue Jan 16, 2018 7:57 am
Forum: emulators
Topic: BeebEm ADFS disc access bug?
Replies: 14
Views: 355

Re: BeebEm ADFS disc access bug?

Can you detail the exact steps to reproduce this error, and also post the disk image you are using?

What version of BeebEm are you using.

It does seem rather weird...
by hoglet
Sun Jan 14, 2018 8:54 pm
Forum: programming
Topic: BeebAsm's Hello World - printing part of file name, not "Hello World"
Replies: 13
Views: 308

Re: BeebAsm's Hello World - printing part of file name, not "Hello World"

occularis wrote:This is probably something painfully simple, but I just can't see it!

Indeed!

This bit doesn't look right:

Code: Select all

    LDX #mytext MOD 256:STA addr
    LDY #mytext DIV 256:STA addr+1

should be:

Code: Select all

    LDA #mytext MOD 256:STA addr
    LDA #mytext DIV 256:STA addr+1

Dave
by hoglet
Sun Jan 14, 2018 7:32 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 473
Views: 27895

Re: Beeb FPGA

Any chance of NuLA support on Beeb FPGA? Coming soon, to a BeebFPGA near you..... :D At the moment it's parked in a branch: https://github.com/hoglet67/BeebFpga/commits/videonula As with Rob's real version, this is essentially a drop-in replacement for the Video ULA component: https://github.com/ho...
by hoglet
Sun Jan 14, 2018 7:56 am
Forum: emulators
Topic: Variations on OSGBPB
Replies: 4
Views: 157

Re: Variations on OSGBPB

There are some better implementation notes on BeebWiki:
http://beebwiki.mdfs.net/OSGBPB

It seems In general the 8-bit systems only implement A=&01 to&08, unless you are running:
- HADFS (&01 to &0B)
- Watford DFS (&01 to &09)

Dave
by hoglet
Sat Jan 13, 2018 9:48 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 52
Views: 1197

Re: SpectROM - Speccy emulator for the Pi co-pro

Hi Rob, This looks really cool. It needs VideoNuLA, as apart from the colours, it uses a new attribute mode that's able to mimic the Spectrum's display. I had to modify the VideoNuLA VHDL to implement this so there's currently only one board in existence that can support it! However, if I get this w...
by hoglet
Sat Jan 13, 2018 4:39 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 52
Views: 1197

Re: SpectROM - Speccy emulator for the Pi co-pro

I haven't looked through the code in detail but I'm not sure it's currently possible to implement a 256-byte transfer on the native Pi core. I couldn't see any use of Tube register 3 (but I didn't spend too much time looking at it). Currently only type 0 and 1 are implemented, but the framework is ...
by hoglet
Sat Jan 13, 2018 4:20 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 52
Views: 1197

Re: SpectROM - Speccy emulator for the Pi co-pro

Isn't the defined - and quickest - way to do this stuff for the Parasite to provoke the Host into initiating a memory transfer? That's true, if what's being transferred is uncompressed screen data. But in the Life example that's being discussed, what's actually being set is effectively compressed, ...
by hoglet
Wed Jan 10, 2018 8:11 am
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

I'm fairly certain that's what I did - I even renamed the elk100 file on the PC to emphasise that it was your version. I take it there's no way to tell the difference in use (*help differences?) No, I think HELP would just show "Advanced DFS 1.00" You could always *SAVE it back out again ...
by hoglet
Wed Jan 10, 2018 7:41 am
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

I've rewritten the EPROM and switched to the Diamondback release of PiTube, and now everything seems to be working! =D> This includes your floppy drivers in ADFS 1.00. I can certainly read disc catalogues and load files. Interesting, and slightly surprising. Can you just confirm for ADFS you were u...
by hoglet
Tue Jan 09, 2018 2:35 pm
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

Ah... no, I'm not sure. Furthermore, I reckon there's a good chance I have downloaded the E version, thinking that "E" stood for Electron. The configuration control for these roms is quite a challenge isn't it! Indeed it is, and it's mostly my fault for using single letter directory names...
by hoglet
Tue Jan 09, 2018 12:47 pm
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

Wouldn't that make the Pi (Z80 mode) incompatible with a BBC though? It does, which is why it's a user settable parameter in cmdline.txt (not params.txt as I mistakenly said earlier). The problem is the Z80 client ROM actually contains some 6502 that's uploaded to the host and this accesses the Tub...
by hoglet
Tue Jan 09, 2018 11:17 am
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

Which MMFS version and ROM file are you using? I'll try and replicate. I've just built myself a similar ROM image: 0x0000 = Blank 0x4000 = U/ESWMMFS.rom from here 0x8000 = Blank 0xC000 = ELK100.rom here Here's the 64K ROM image: elk_eswmmfs_adfs.zip I've put the AP5 into Mode 2 (J1 missing, J2 pres...
by hoglet
Tue Jan 09, 2018 8:25 am
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

That's odd... I've now got j1 and j2 set up correctly for MMFS, but I still get a Card? Error with an MMC board connected to SK3. This board and card work fine with a BBC, but I'm not certain I've tested them with MMFS, only with the old DFS0.9 MMC system. Does this mean I need to do something diff...
by hoglet
Tue Jan 09, 2018 8:23 am
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

PiTubeDirect Cobra works too, with one exception: *fx 151 230 n seems to do nothing at all. Anyone know why? On the ELK the address of the tube is different. So you need to do *FX 147 230 n Also, do update to the DiamondBack release. It fixes a serious bug in the GPU code, and also adds an Elk mode...
by hoglet
Mon Jan 08, 2018 9:51 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 39
Views: 1012

Re: My New Acorn Atom :)

waltermixxx wrote:Once I install the 32K memory and have memory from #0000 to #7FFF, will the 32K ram programs/games on the ATOMMC Program Compilation run?

They should work fine.

Dave
by hoglet
Mon Jan 08, 2018 12:40 pm
Forum: wanted
Topic: L6925/6/8 regulator
Replies: 3
Views: 82

Re: L6925/6/8 regulator

crj wrote:I'm going to place a Mouser order this week. If this is suitable I could tack it on and either stick it in an envelope to you or bring it to the meeting the weekend after next.

That would do perfectly. Thanks!

Dave
by hoglet
Mon Jan 08, 2018 12:18 pm
Forum: wanted
Topic: L6925/6/8 regulator
Replies: 3
Views: 82

L6925/6/8 regulator

Hi all, Does anyone happen to have a spare ST Microelectronics L6925, L6926 or L6928 regulator in an MSOP8 package? It's to try to repair a friend's GOP XC3S200: GOP_XC3S200.angle.jpg The regulator is meant to generate 1.2V, but is currently generating 2.9V :shock: It seems the output MOSFET is shor...
by hoglet
Mon Jan 08, 2018 7:47 am
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 39
Views: 1012

Re: My New Acorn Atom :)

waltermixxx wrote:Would this be ok for my 32k ram upgrade, (this is from Briel's Apple 1 replica)

That should be perfect!

Dave
by hoglet
Sun Jan 07, 2018 10:30 pm
Forum: hardware
Topic: MMFS Development and Support
Replies: 729
Views: 37256

Re: MMFS Development and Support

VDFS does indeed do this and I think JGH may have worked out somewhere to store the flag to say if the masquerading is currently on or off. In MMFS there already is a bit of state (bit 6) in the private workspace byte (stored in &DF0-&DFF) to this effect. It's manipulated by *OPT 5,N, but a...
by hoglet
Sun Jan 07, 2018 8:53 pm
Forum: hardware
Topic: Fault finding index
Replies: 86
Views: 16899

Re: Fault finding index

Beeb Model B was working earlier today. It got left on all afternoon and when I came back in the evening and it seemed to have hung. Video was still active, but pressing BREAK had no effect. On power cycling I got a blank video display with a flashing cursor and a endless Beeeeeeeep. So I plugged th...
by hoglet
Sun Jan 07, 2018 8:38 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 39
Views: 1012

Re: My New Acorn Atom :)

R-/W to /WE That's the one you need to be really careful about. For reliable writes, the WE signal of a RAM should be R-/W gated with Phi2, like the NWDS signal on the on the Atom Schematic is (i.e. NWDS should be low, only when R-/W is low and Phi2 is high). You could connect NWDS to the RAM /WE w...
by hoglet
Sun Jan 07, 2018 8:32 pm
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

Regarding bank switching, I had assumed this would be something done manually by the user making the pokes described in the manual. It can't be done from within a sideways rom, presumably, as to do so would pull out the rug from under the feet of the currently executing rom. I think the idea is you...
by hoglet
Sun Jan 07, 2018 6:20 pm
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

So if I went with ADFS my rom would look like this: Mode 3 0000-2FFF Spare and not really usable as there isn't anything else which uses a 4k overlay. 4000-6FFF ADFS 1.31 (needs patching with Elk hardware addresses) 8000-BFFF Spare - could use for any 16k ROM though C000-FFFF EMMFS @1900 Yes, that ...
by hoglet
Sun Jan 07, 2018 5:20 pm
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

Someone really should draw a family tree for all ADFS versions! There was another branch that might be of interest: ADFS 1.31 (SCSI) and ADFS 1.32 (IDE patched my Michael). The image for ADFS 1.31 is here (amongst other places): http://archive.retro-kit.co.uk/BBC.nvg.org/rom/Acorn/fs/index.html And ...
by hoglet
Sun Jan 07, 2018 4:57 pm
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15922

Re: P.R.E.S. AP5 - Original and Re-Design

I can have a stab at answering these questions... 1) On page 12 of the manual the text at the bottom implies that the 62256 is the only supported SRAM type, but the table above states 16k RAM for Modes 2 & 3. Does this mean that these modes don't work with the 62256? That's possibly a typo in th...

Go to advanced search