Search found 431 matches

by dominicbeesley
Tue Nov 21, 2017 2:02 pm
Forum: hardware
Topic: Electron 6502 desolder / socket pics
Replies: 7
Views: 320

Re: Electron 6502 desolder / socket pics

And is there a way to "take over" the cpu signals i.e. RnW, A, D for DMA?
by dominicbeesley
Tue Nov 21, 2017 1:59 pm
Forum: hardware
Topic: Electron 6502 desolder / socket pics
Replies: 7
Views: 320

Re: Electron 6502 desolder / socket pics

Oooh! Another one! I've just started using the xeropage de0nano/fpag adaptor. And have started thinking about another similar idea! Will you be selling them?

D
by dominicbeesley
Tue Nov 21, 2017 1:56 pm
Forum: hardware
Topic: BeebSID
Replies: 921
Views: 76274

Re: BeebSID

woop woop, I'll get me whistle...no hang on which of the boxes did I pack the SID....
by dominicbeesley
Tue Nov 21, 2017 12:40 pm
Forum: hardware
Topic: NuLA demos
Replies: 130
Views: 5354

Re: NuLA demos

Thanks for posting!

I wish I could have made it to ABUG

D
by dominicbeesley
Tue Nov 21, 2017 11:03 am
Forum: hardware
Topic: ZX81 emulator
Replies: 15
Views: 215

Re: ZX81 emulator

Aha, got it - I thought you might have actually got the gcc cross compiler tools working on there!

D
by dominicbeesley
Tue Nov 21, 2017 10:20 am
Forum: hardware
Topic: ZX81 emulator
Replies: 15
Views: 215

Re: ZX81 emulator

Nice one rob. Another triumph!

I'm not clear where the pdp11 comes in?
by dominicbeesley
Mon Nov 20, 2017 10:49 am
Forum: projects
Topic: Happy Mrs Chicken!
Replies: 21
Views: 968

Re: Happy Mrs Chicken!

I'll look forward to it as will the daughter!

I know how you feel I have a workshop cum cellar, an office, a storage unit and an industrial unit filled with my started projects...it's difficult to find the time to fit work in, I'm very rarely bored though!

D
by dominicbeesley
Sun Nov 19, 2017 3:39 pm
Forum: projects
Topic: Happy Mrs Chicken!
Replies: 21
Views: 968

Re: Happy Mrs Chicken!

Excellent,

I spotted this yesterday, even with the minimalist game-play it kept the three year old quiet for 20 minutes.

Do you plan on making more of this?

D
by dominicbeesley
Sun Nov 19, 2017 3:30 pm
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

Re: read / write to JIM

Thanks all, interesting stuff Thanks Pernod for the details. JGH, all points taken, looks like the EE/select scheme was never actually used: why it was still on a seemingly current App note dated 1992 I've no idea! I should have remembered the EE being used for OSBYTE&79 and the keyboard routine...
by dominicbeesley
Sun Nov 19, 2017 12:34 am
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

Re: read / write to JIM

It would depend on what kind of access (block transfers for say a RAM disc, or what I'm doing) or more random transfers whether an extra few us per 256 accesses or would justify losing the ability to do a quick zero test on an index register. But I take your point. I'd say the app note (see attachme...
by dominicbeesley
Sat Nov 18, 2017 3:47 pm
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

Re: read / write to JIM

Thank JGH, I think I was being over optimistic as I've always taken the attached 1MHz bus app not as Gospel 1Mhzbus_appnote.pdf Weird that at this end it's claiming 12:09pm->11:35am on the same day! I suspect that the forum software / server / something is still operating on BST (or something like t...
by dominicbeesley
Fri Nov 17, 2017 12:53 pm
Forum: hardware
Topic: BBC Master Issues with Replacement CMOS Battery
Replies: 5
Views: 132

Re: BBC Master Issues with Replacement CMOS Battery

The CMOS IC should be soldered in. Have you got any test equipment, that sounds like the RTC's clock oscillator may have stopped it would be worth having a prod to see if the RTC clock is runing. I had similar problems with my homebrew machine's RTC clock dropping out causing reading time to hang. Y...
by dominicbeesley
Fri Nov 17, 2017 11:18 am
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

Re: read / write to JIM

Enormous thanks JGH once again! I wasn't being petulant in my second post - I just assumed nobody had anything JIM based...and it was 1.09am->12.35pm so I left eleven and a half hours, I'm still working on the time-travel machine but I suspect that I may need more than a 1MHz bus to drive it... I've...
by dominicbeesley
Fri Nov 17, 2017 12:49 am
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

Re: read / write to JIM

Well, it kinda works...slowly. the 1MHz bus speed, is not the problem but using OSGBPB is S.L.O.W. looks like I'll need a better way of loading big chunks of data in

D
by dominicbeesley
Thu Nov 16, 2017 7:42 pm
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

Re: read / write to JIM

Thanks all, I take your point crj, but I'm not (solely) using this as expansion RAM it is a hardware item that happens to have a big chunk of RAM and it would be beneficial to be able to easily read / write files into / from that RAM by some method, preferably without using large buffers in normal I...
by dominicbeesley
Thu Nov 16, 2017 11:35 am
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

Re: read / write to JIM

I guess not then! Is there anyone out there who has expansion RAM in JIM? If I knock up some tools would there be interest, any help with testing? Also, is there an official way to work out what expansion RAM is fitted if any? I'll probably just make them work blind for now... I'm thinking: JLOAD <f...
by dominicbeesley
Thu Nov 16, 2017 12:09 am
Forum: hardware
Topic: read / write to JIM
Replies: 28
Views: 581

read / write to JIM

Before I start coding...

I'm currently working on device that exposes memory in the JIM (page &FD) are and uses the page wide paging registers. Are there any standard tools for reading / writing files to / from JIM?

D
by dominicbeesley
Thu Nov 09, 2017 12:00 pm
Forum: hardware
Topic: Would anyone mind burning me a Starstick ROM?
Replies: 12
Views: 363

Re: Would anyone mind burning me a Starstick ROM?

Has it broken the machine or just that ROM? Which ROM slot(s) did you try them in? When I tried them they were in a ZIF socket so it may just need the pins given a scrape with a pen knife to shine the IC pins up the sockets can be more difficult to clean without stressing the spring contacts. I know...
by dominicbeesley
Tue Nov 07, 2017 8:58 am
Forum: hardware
Topic: Unix on the Beeb
Replies: 36
Views: 1018

Re: Unix on the Beeb

Nice one Rob, I had a go at getting ucLinux to boot a few years ago on the Sprow ARM copro, it worked ok! I can't remember now how I had it set up in terms of discs, I suspect it ran from RAM disc... I then went down the rabbit hole of adding a Flash ROM to the board and trying to get that to hold t...
by dominicbeesley
Sun Nov 05, 2017 5:37 pm
Forum: hardware
Topic: 6809 experiments
Replies: 129
Views: 5887

Re: 6809 experiments

Thanks Graham,

I'll look around at the Vectrex forum, I will also see if I can track down any active Coco programmers at some point.

I'm sure Any stories you, or JGH have would be received with interest!

D
by dominicbeesley
Thu Nov 02, 2017 11:30 am
Forum: hardware
Topic: Daisy-chaining 2 FDD
Replies: 7
Views: 163

Re: Daisy-chaining 2 FDD

I usually just pop the connector off and untwist, reset in a vice, (or other suitable press - I used an ikea cupboard door the other day, not recommended but it worked, unlike the door afterwards).... This one looks to be untwisted http://www.ebay.co.uk/itm/Fast-Flexible-Cool-DUAL-FLOPPY-DRIVE-RIBBO...
by dominicbeesley
Wed Nov 01, 2017 2:34 pm
Forum: hardware
Topic: Would anyone mind burning me a Starstick ROM?
Replies: 12
Views: 363

Re: Would anyone mind burning me a Starstick ROM?

Hi commie_user, I've sent you a PM
by dominicbeesley
Tue Oct 31, 2017 7:45 pm
Forum: hardware
Topic: Test ROM
Replies: 15
Views: 317

Re: Test ROM

The ROM that Graham posted up doesn't do anything that spectacular, are you talking about the same thing?

D
by dominicbeesley
Tue Oct 31, 2017 4:44 pm
Forum: hardware
Topic: Test ROM
Replies: 15
Views: 317

Re: Test ROM

Files are attached.

I can't recall the exact details but I remember ending up with something like that when I broke the nmi pin on the wd1770 upgrade and noise would cause random NMIs...

You can read ssds using the tools here: https://swhs.home.xs4all.nl/bbc/mmbeeb/windows.html

D
by dominicbeesley
Tue Oct 31, 2017 2:35 pm
Forum: hardware
Topic: Test ROM
Replies: 15
Views: 317

Re: Test ROM

Do you want a physical ROM blowing or just the binary extracting from the SSD?

Either way post up the SSD and PM me your address if you want me to blow and EEPROM for you...

D
by dominicbeesley
Tue Oct 31, 2017 2:33 pm
Forum: hardware
Topic: Master 128 PSU schematic
Replies: 8
Views: 291

Re: Master 128 PSU schematic

Thanks Ottly, Mark, I finally dug out some 3W resistors and replaced R2, R3, it now starts up instantly again. One (I can't remember which but I think R2) had gone to 275K from 180K. All the electrolytics tested fine for both ESR and leakage, though I'd already removed the main smoothers before I te...
by dominicbeesley
Tue Oct 31, 2017 2:27 pm
Forum: hardware
Topic: part list bbc psu ?
Replies: 18
Views: 942

Re: part list bbc psu ?

For completeness - on the master PSU I just repaired R2, R3 are both 180k rather than 100k
by dominicbeesley
Thu Oct 26, 2017 1:56 pm
Forum: hardware
Topic: 6809 experiments
Replies: 129
Views: 5887

Re: 6809 experiments

Straying slightly OT into VHDL, I'm trying to model the Mk.2 board before I commit to fabrication. I've swapped over to using TI 74CB3T6211 bidirectional level shifters instead of 74XX4245s. I'm not clear how to model them in VHDL. The naive 1st cut (delays not implemented yet) seems to work but I'm...
by dominicbeesley
Tue Oct 24, 2017 11:08 am
Forum: hardware
Topic: high density disks
Replies: 160
Views: 21768

Re: high density disks

Thanks for the info Martin, I will have a play with this. I was hoping it wouldn't require modding the drive, it's a shame that they didn't multiplex pin 2 i.e. only pull it low/high when that particular drive is selected... I need to go on a mining expedition in my storage unit to find my store of ...
by dominicbeesley
Mon Oct 23, 2017 2:26 pm
Forum: hardware
Topic: high density disks
Replies: 160
Views: 21768

Re: high density disks

I've been reading this thread with interest and I'm going to have a play at some point. I have a question about pins 4 and 2 on the floppy cable. Was there consensus that this was used consistently on 3.5" drives as an output? For 5.25" HD this is an output, does it switch both connected d...

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