Search found 892 matches

by dominicbeesley
Thu Nov 21, 2019 12:04 am
Forum: projects
Topic: Beebem on Github
Replies: 126
Views: 11680

Re: Beebem on Github

I've taken a copy of BeebEm from Github to work on off-line (Plus net have screwed up my house move and I've no broadband for a week other than mobile tethering) There appear to be two Stardot versions: https://github.com/stardot/beebem https://github.com/stardot/beebem-windows I'm I right in thinki...
by dominicbeesley
Mon Nov 18, 2019 10:51 am
Forum: hardware
Topic: A blitter for the beeb?
Replies: 110
Views: 10874

Re: A blitter for the beeb?

@mr-macrisc, if I get the triangle plotting done something like that should be possible - though it would also maybe require textured triangle plotting to get enough shades to make it convincing. I looked at Elite but have to say the amount of code to wade through was a bit over-facing - I'd definit...
by dominicbeesley
Sat Nov 16, 2019 12:40 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 110
Views: 10874

Re: A blitter for the beeb?

Thanks for the continuing interest - I know this has been going on for a long time now but real life has to take precedence...sometimes Yes, the CPU when accessing chip RAM/Flash can run at up to 8MHz and that does include when accessing sideways RAM/ROMS. As you say on the Master the ROM slots are ...
by dominicbeesley
Fri Nov 15, 2019 4:42 pm
Forum: software: other
Topic: software troubleshooter for beeb hardware SelfTestOs
Replies: 45
Views: 5476

Re: software troubleshooter for beeb hardware SelfTestOs

Levels are all good and this is an otherwise impeccably behaved machine. I didn't have a decent scope on hand to check levels but the LA has a threshold setting and I tested at 1.4V and 2.0V and the data and address lines looked ok. I've attached the E000 version to have a look at. I did some furthe...
by dominicbeesley
Fri Nov 15, 2019 1:45 pm
Forum: software: other
Topic: software troubleshooter for beeb hardware SelfTestOs
Replies: 45
Views: 5476

Re: software troubleshooter for beeb hardware SelfTestOs

I couldn't resist one last "tinker" before putting the master in its box: I hooked up a logic analyzer to check for any interrupts or other spurious activity that might upset the ULA or CRTC but the writes look to be working perfectly and the correct data are being sent when the mode0 screen is init...
by dominicbeesley
Fri Nov 15, 2019 1:00 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 110
Views: 10874

Re: A blitter for the beeb?

The Master test has now completed it's initial stage - getting Tricky's OS Tester ROM to run. There will be a lot more to do on the Master before it's finished: - merge back changes for Elk (clock stretch handling) - merge M128 RDY handling - a lot of work will need to be done on register placement ...
by dominicbeesley
Fri Nov 15, 2019 12:50 pm
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

I've not forgotten about this - I'm still slowly working away at this but I'm in the middle of a house move so probably won't do much for the next couple of weeks It took a while to get DNS working - but it has forced me to add some API changes to allow data to be read/written byte by byte which wil...
by dominicbeesley
Fri Nov 15, 2019 11:39 am
Forum: software: other
Topic: software troubleshooter for beeb hardware SelfTestOs
Replies: 45
Views: 5476

Re: software troubleshooter for beeb hardware SelfTestOs

Thanks Both, Tricky, I will post up once I've worked out why it occasionally fails to switch to mode 0. So far all I've done is ORG'd the code at E000 to swerve any issues with Hazel overlays 1024MAK, the 27C512 thing as as you say but shouldn't matter for this test, as I said in the other post I en...
by dominicbeesley
Thu Nov 14, 2019 3:55 pm
Forum: software: other
Topic: software troubleshooter for beeb hardware SelfTestOs
Replies: 45
Views: 5476

Re: software troubleshooter for beeb hardware SelfTestOs

To partly answer my own question it doesn't quite work on a Master. I've been testing this on my "known good" machine. Instead of using a 27C512 I've been using a Sundby MOS switcher with a 39SF040. If I programmed the ROM into the bottom of this it didn't work, nor if I repeated it. Looking at what...
by dominicbeesley
Wed Nov 13, 2019 8:42 pm
Forum: software: other
Topic: software troubleshooter for beeb hardware SelfTestOs
Replies: 45
Views: 5476

Re: software troubleshooter for beeb hardware SelfTestOs

Hello, I need to do some master testing and this seems like a possibly good starting point. Should I be able to blow this to a 27c512 and set lk9. If so which bank in the 27512 should I program it to? Looking on mdfs.net it looks like it should be possible to just plonk it at the start? Is this the ...
by dominicbeesley
Wed Nov 13, 2019 1:05 pm
Forum: wanted
Topic: Acorn System Replica boards
Replies: 14
Views: 360

Re: Acorn System Replica boards

Ah, ok. I was looking for something more original but might go for these later.

D
by dominicbeesley
Wed Nov 13, 2019 10:32 am
Forum: wanted
Topic: Acorn System Replica boards
Replies: 14
Views: 360

Re: Acorn System Replica boards

How close to the originals are these boards, are they true replicas or modern reimaginings?

D
by dominicbeesley
Tue Nov 12, 2019 12:36 pm
Forum: wanted
Topic: Acorn System Replica boards
Replies: 14
Views: 360

Re: Acorn System Replica boards

Same here! If you need any help give me a shout!

D
by dominicbeesley
Tue Nov 12, 2019 11:16 am
Forum: wanted
Topic: Acorn System Replica boards
Replies: 14
Views: 360

Re: Acorn System Replica boards

Thanks all, Thanks for the offer Bram, I'll have a go myself at converting Eagle to KiCad - I don't want anybody to go to any trouble - though if you do have a go let me know. I was planning on making my own boards anyway but thought if there were people with unused pcb's then that would be a good s...
by dominicbeesley
Mon Nov 11, 2019 11:45 pm
Forum: wanted
Topic: Acorn System Replica boards
Replies: 14
Views: 360

Re: Acorn System Replica boards

I've contacted the ebay seller to see if he's making more. If not I might have to redo these in Kicad...

Thanks

D
by dominicbeesley
Mon Nov 11, 2019 3:32 pm
Forum: wanted
Topic: Acorn System Replica boards
Replies: 14
Views: 360

Acorn System Replica boards

I found some old listings for Acorn System 1/3/5 replica boards on ebay but there don't seem to be any current listings - to get me started with my rack system I'd love to get hold of any unused boards or sets. Does anyone have any they'd like to part with - I've not got much money at present though...
by dominicbeesley
Wed Oct 30, 2019 11:46 am
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

Thanks davidb, I did look at bootp too - it also looks to be as much work (a lot of low level ARP stuff that I don't understand how to do on the Wiznet but could work out). If I did bootp I'd probably do dhcp too as that is more useful and common. For general information, attached is the current, ra...
by dominicbeesley
Wed Oct 30, 2019 11:03 am
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

Thanks both, Sweh, now I have the API then I mean to build HostFS on top of it so it won't really be optional. The full page is pretty much necessary. Claiming NMI isn't an option as it needs to hold information long-term about what sockets are in use. Also, it needs to do this while it isn't the se...
by dominicbeesley
Tue Oct 29, 2019 3:43 pm
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

The other thing I mean to ask in my ramblings this morning - would not having DHCP be a showstopper - it looks like a big chunk of work!
by dominicbeesley
Tue Oct 29, 2019 2:20 pm
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

The probe isn't "wrong" or the problem - merely that the small amount of loading introduced by the probe reduces the noise/glitches enough to cure the problem - cure to the problem is to load the signal with a bit of capacitance. Reading around the net this is a common problem with these wiznet chip...
by dominicbeesley
Tue Oct 29, 2019 11:04 am
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

I've not been asleep on this. I have made up a board and...well it didn't quite work. The WizNet module is very sensitive to any glitches or noise and when transferring bytes a glitch can cause a double access to occur and bytes are skipped. On the mk.1 board I'd added a 220pF cap to the nRD signal ...
by dominicbeesley
Sun Oct 27, 2019 9:12 am
Forum: hardware
Topic: Screen shadow memory
Replies: 35
Views: 2057

Re: Screen shadow memory

Indeed. In porting the 1.20 mos to the 6809 I moved most of the vdu code you be in the c000 region to allow this. I have never got round to making a fully buildable 6502 mos 1.20 source but it wouldn't be that difficult (mainly making sure jump tables and the like are properly built). Would there be...
by dominicbeesley
Wed Oct 23, 2019 7:21 pm
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

New boards have arrived...not sure when I'll get a chance to solder one up and test that it works.

They look good and as JLCPCB label their total cost correctly (not including carriage) I didn't get fleeced by duty!
20191023_154142-s.jpg
D
by dominicbeesley
Wed Oct 23, 2019 6:44 pm
Forum: hardware
Topic: Electron 1MHz Clock regen circuit
Replies: 8
Views: 324

Re: Electron 1MHz Clock regen circuit

Thanks Phil, t65 will run with a 128MHz clock so long as you only clken it once every few cycles - I've had it going at 32MHz happily enough but for my purposes 8 suffices! (You need to use an SDC constraint for multicycle paths, it's a bit involved but once these are set it all works ok and Quartus...
by dominicbeesley
Wed Oct 23, 2019 9:12 am
Forum: hardware
Topic: Electron 1MHz Clock regen circuit
Replies: 8
Views: 324

Re: Electron 1MHz Clock regen circuit

Thanks Phil, That's more or less what I'm doing, I have a fast clock at 128MHz derived from a local 50MHz crystal and PLL (which just happened to be on the dev board). That is then divided down to 8MHz (currently the fastest processor speed, I might go back to 16MHz), 4, 2 and 1MHz clocks. The 2 Mhz...
by dominicbeesley
Tue Oct 22, 2019 4:15 pm
Forum: hardware
Topic: Electron 1MHz Clock regen circuit
Replies: 8
Views: 324

Re: Electron 1MHz Clock regen circuit

Yes thanks, I'd got that - after some initial confusion over the circuit in the service manual which has phi's out of the ULA and out of the cpu...
by dominicbeesley
Tue Oct 22, 2019 12:07 pm
Forum: hardware
Topic: Electron 1MHz Clock regen circuit
Replies: 8
Views: 324

Re: Electron 1MHz Clock regen circuit

Thanks Hoglet, that's exactly what I wanted. Yes, I'll be doing it in the blitter fpga, I'm aware of the noise issues and run most signals through a few flip-flops for metastability and check for spurii. I've been working on a clock regen component for the Elk that can recover a noise free 2MHz cloc...
by dominicbeesley
Tue Oct 22, 2019 11:30 am
Forum: hardware
Topic: Electron 1MHz Clock regen circuit
Replies: 8
Views: 324

Electron 1MHz Clock regen circuit

I'm struggling to work out the 1MHz access cycles on the Electron. The nearest I've got is the Acorn Application Note 015 which has a diagram for a 1MHz regen circuit. However, the diagram makes little sense to me, I suspect there might have been either an error during drafting or something has gone...
by dominicbeesley
Mon Oct 21, 2019 11:16 am
Forum: hardware
Topic: A blitter for the beeb?
Replies: 110
Views: 10874

Re: A blitter for the beeb?

Sorry @jregel, I missed this post somehow. Here's a general update of progress. Currently implemented or in alpha: - cpu: 65c02, 65816*, z80, 68008, 6809, 6309 and ability to switch to a 6502A soft-core (t65) - two sets of sideways ram/rom which can be switched easily (to allow one set of roms for r...
by dominicbeesley
Sun Oct 20, 2019 9:14 am
Forum: hardware
Topic: HostFS+TCPIP
Replies: 68
Views: 1884

Re: HostFS+TCPIP

That's what i thought. But it doesnt - see Sprows comments earlier. I want to make whatever i do compatible with his but I'm fast thinking that might be impossible if i can't find what error numbers he used. So far I've been returning an Exxx type number but then any software that relied on those wo...