Search found 19 matches

by Andrewcee
Sun Dec 03, 2017 10:33 am
Forum: hardware
Topic: high density disks
Replies: 162
Views: 22904

Re: high density disks

Can now use both 3.5 & 5.25" disks with mod fitted - not at same time, at the moment - at 'flick of a switch'. Fitted toggle switch to select the 16meg clock mod input to either 16meg for 3.5" drives or 8meg for 5.25" drives. Switched to 5.25"/8MHz Master/BBC runs as original...
by Andrewcee
Fri Nov 17, 2017 10:48 am
Forum: hardware
Topic: high density disks
Replies: 162
Views: 22904

Re: high density disks

Hi Martin, Yesterday folded & sprayed some ali sheet and mode a housing for a couple of drives, made data & ps cables, and all is working well. Had to do some 'head aligning' on one of the drives, but now the three drives I have will each read/write disks from one another. Next job is to wor...
by Andrewcee
Fri Nov 10, 2017 11:03 pm
Forum: software: other
Topic: BBC Basic for Z80
Replies: 26
Views: 1158

Re: BBC Basic for Z80

Have succeeded running Z80 basic program on Master with Pi copro earlier today, a new first. Used half dozen lines of code looping round with calls via oscli to format & verify a dozen floppies. Definitely a 27128 needed or equivalent swr. Had cpm running from a turbo MMC albeit have still to wo...
by Andrewcee
Fri Nov 10, 2017 10:32 pm
Forum: introduce yourself
Topic: 30 Years On...
Replies: 9
Views: 358

Re: 30 Years On...

Thanks folks for the warm welcome. Realised how rusty my 6502 assembler skills have become when working on my prom programmer. Great way to get going again. Been great getting a 3.5" disk solution working with help from Martin (albeit been unable to get DFS beyond 2.24 on mos 3.2 working) and m...
by Andrewcee
Fri Nov 10, 2017 10:13 am
Forum: introduce yourself
Topic: 30 Years On...
Replies: 9
Views: 358

30 Years On...

How can it be? Some 30 years have passed since I last fired up my Beeb! Spectrum too, and both worked first time. Let's try that on a modern-day PC, shall we?! A month later... I've acquired a Master 128, got a 3.5" disk set up working (thanks Martin), changed the psu caps in my Beeb (stunk for...
by Andrewcee
Fri Nov 10, 2017 9:39 am
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1021
Views: 79609

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

Managed to get CP/M working last night with Turbo MMC. Seems it likes a CP/M 'system disk' in drive 0 or A:. Still to succeed running anything other than dir a: & dir b: as machine (Master) hangs. Will try with floppy, i.e. DFS, once I can get Omnifop running on PC to write correctly formatted d...
by Andrewcee
Fri Nov 10, 2017 9:32 am
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1021
Views: 79609

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

Recently got to know how the STL256 rom select works on main pcb having attempted the 'diy 256meg rom/ram upgrade' on my Beeb, essentially it takes over from the rom select chip, ic76. Makes sense as it has to also switch its own roms and swr. Best I can see can use only up to 128k Roms on the main ...
by Andrewcee
Thu Nov 09, 2017 11:01 am
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1021
Views: 79609

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

Another success story... Now to get each of the processor options working. Brilliant fun, thanks!!
by Andrewcee
Thu Oct 26, 2017 5:40 pm
Forum: hardware
Topic: high density disks
Replies: 162
Views: 22904

Re: high density disks

V2 MDM built & installed in my Master, can clearly see switching on scope between 8 & 16 meg. Thanks Martin!!
by Andrewcee
Sun Oct 22, 2017 10:51 pm
Forum: hardware
Topic: high density disks
Replies: 162
Views: 22904

Re: high density disks

Good hearing from you Martin, and thanks for your reply. Thanks too for the mountains of info you've posted, couldn't have got my dual 35 set up working without your help! Have dual 35 Alps drives running on Master as drives 0&1, think they work as 0-3 although more testing required. Alps drives...
by Andrewcee
Sun Oct 22, 2017 12:07 am
Forum: hardware
Topic: high density disks
Replies: 162
Views: 22904

Re: high density disks

I have read this post several times - so much to take in. All good stuff, my thanks to all. Thought I'd have a go connecting a couple of Alps 35 floppies from the loft to a recently purchased Master fitted with Econet and VL1772 02PC - if only my old B had Econet, could be fun. Proof of concept,... ...
by Andrewcee
Sat Oct 21, 2017 9:42 am
Forum: hardware
Topic: Fitting a Solidisk 256Kb 2/4Meg board
Replies: 9
Views: 1413

Re: Fitting a Solidisk 256Kb 2/4Meg board

Having run the square root benchmark with (allegedly, been so long 25 years plus since I programmed it!) Basic 4 in STL board...
4Meg integer: 145
4Meg floating point: 158
Ditto 2Meg: 291 & 317

IE. Twice speed on 4Meg, and small increase using integers. Learn something everyday!

Andrew
by Andrewcee
Sat Oct 21, 2017 9:09 am
Forum: hardware
Topic: Solidisk 256 rehab
Replies: 6
Views: 609

Re: Solidisk 256 rehab

Great stuff, learning fast!

Have I read somewhere it suggested all 16 or 32 of 'base memory' could be swapped to 4Meg with suitable add-on and logic? Probably not feasible or too expensive else Solidiak may well have done something similar on their 4Meg board.

Lots of reading to do!!

Andrew
by Andrewcee
Sat Oct 21, 2017 9:02 am
Forum: hardware
Topic: CUB 451 with lots of interference
Replies: 27
Views: 1137

Re: CUB 451 with lots of interference

Thanks... Guessed as much. I feel an order to farnell coming on. Off track - been reading (and re-reading) Martin's write ups on 3.5" disks on the Beeb. Just so happens I've a socketed VLI1772 in my new Master. Unfortunately the 1770 is soldered into my beeb's' Solidisk board. Appears 1772 P2 0...
by Andrewcee
Sun Oct 15, 2017 12:27 pm
Forum: hardware
Topic: Solidisk 2/4Meg 256k card issue
Replies: 17
Views: 792

Re: Solidisk 2/4Meg 256k card issue

Had same problem with my STL256 on 4Meg. Take clock from pin 5 IC 44, works fine at 4Meg. Never worked reliably using R106 feed. I posted thoughts on STL256 on another post, if only I could find it?!
by Andrewcee
Sun Oct 15, 2017 12:24 pm
Forum: hardware
Topic: Solidisk 256 rehab
Replies: 6
Views: 609

Re: Solidisk 256 rehab

Still using mine! Turned on my BBC B for first time in over 25 years month ago (been on loft the, then in garage past 8 years) it fired up okay straight away! An hour last psu caps failed, since replaced. Same thing happened couple weeks before in Henry vacuum cleaner, same capacitor. My STL256 neve...
by Andrewcee
Sun Oct 15, 2017 12:02 pm
Forum: hardware
Topic: CUB 451 with lots of interference
Replies: 27
Views: 1137

Re: CUB 451 with lots of interference

Quick thought, having repaired my Cub recently. I found circuit diagrams by searching web, noted too there were several versions of the main pcb. Interesting trying to make sure I was working from the correct version when fault finding on the switch mode supply. Had the thyristor driving the degauss...
by Andrewcee
Sun Oct 15, 2017 7:29 am
Forum: hardware
Topic: LCD TVs and monitors for use with BBCs
Replies: 186
Views: 55741

Re: LCD TVs and monitors for use with BBCs

Thanks Mark... image.jpeg Update: Reason for going the 'vga' route was to open option to buy recycled PC monitor rather than £10 tv seen on left which had severe wobble on top couple lines on screen with BBC RGB to Scart input. Wobble now gone (?) with scart input, display much better quality then 8...
by Andrewcee
Sat Oct 14, 2017 3:33 pm
Forum: hardware
Topic: LCD TVs and monitors for use with BBCs
Replies: 186
Views: 55741

Re: LCD TVs and monitors for use with BBCs

Thanks for info. Bought 8820 for £20, old TV at charity shop for £10, cardboard box 8220 packed in for free, and brilliant results. Few little flashing spots only when screen full of text hardly noticeable, else black. Great job! New Master on left with video board, original B on right running Solid...

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