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by cmorley
Sun Apr 05, 2020 11:49 am
Forum: hardware
Topic: New SCSI Host Adaptor
Replies: 40
Views: 905

Re: New SCSI Host Adaptor

Oh I remembered about the open collector then forgot when I posted. What hoglet wrote! Verilog does have synthisisable for loops but you don't really need that for 8 lines. edit: in case you do though you do it along these lines. code pinched from another forum... integer i; reg [7:0] io_internal; a...
by cmorley
Sun Apr 05, 2020 10:57 am
Forum: hardware
Topic: New SCSI Host Adaptor
Replies: 40
Views: 905

Re: New SCSI Host Adaptor

// assign scsi_nACK = ~scsi_ACK; assign scsi_nACK = (~scsi_ACK) ? 1'b0 : 1'bZ; // assign scsi_nSEL = ~scsi_SEL; assign scsi_nSEL = (~scsi_SEL) ? 1'b0 : 1'bZ; // assign scsi_nRST = bbc_nRST; assign scsi_nIRQ = (bbc_nRST) ? 1'b0 : 1'bZ; Does that look right? Not so sure about the databus. I'll come b...
by cmorley
Sun Apr 05, 2020 10:11 am
Forum: hardware
Topic: New SCSI Host Adaptor
Replies: 40
Views: 905

Re: New SCSI Host Adaptor

What is the current capability of the CPLD pins? You need 23mA sink (per pin) to drive SCSI-1 with a single terminator I think.
by cmorley
Mon Mar 30, 2020 2:12 pm
Forum: programming
Topic: BASIC keywords query: hex 8D,8E,CE,FF
Replies: 3
Views: 128

Re: BASIC keywords query: hex 8D,8E,CE,FF

8E is OPENIN in BASIC 2.
ref: BASIC ROM USER GUIDE by Mark Plumbley

Couldn't see the other codes in the list.
by cmorley
Sun Mar 29, 2020 5:10 pm
Forum: software: other
Topic: Ample wow
Replies: 11
Views: 524

Re: Ample wow

My only source aside from the various emulators source was the M5000 schematic posted on stardot a while ago... I don't own a M500 or M5000 to check first hand. Interesting though the snippet billcarr posted - which is presumably what you recall? They must have been talking about the player code I t...
by cmorley
Fri Mar 27, 2020 5:24 pm
Forum: software: other
Topic: Ample wow
Replies: 11
Views: 524

Re: Ample wow

Rob, Ample or the M5000? AFAIK the hardware doesn't produce any interrupts. You'd have to go bare metal for a game or demo...
by cmorley
Fri Mar 27, 2020 2:23 pm
Forum: software: other
Topic: Ample wow
Replies: 11
Views: 524

Re: Ample wow

I've implemented the M5000 on a project... Tell us more. It's the thing I mentioned to you at the last ABUG Tricky, the low cost Cortex M7 1MHz bus board. I made the dev board (12 months ago!) around the time dp11 posted about the Pi 1MHz bus thing. It was one of those dev boards I sent to KF for t...
by cmorley
Fri Mar 27, 2020 9:31 am
Forum: software: other
Topic: Ample wow
Replies: 11
Views: 524

Re: Ample wow

I've implemented the M5000 on a project and the more I learn about it the more I am saddened that it wasn't really taken advantage of. The tools just weren't there. I'd love to know what musical gems would be out there if it ever got 1/2 the love the mod scene or the Gravis Ultrasound got... A moder...
by cmorley
Fri Mar 20, 2020 2:03 pm
Forum: hardware
Topic: VideoNuLA and 6845 questions
Replies: 13
Views: 442

Re: VideoNuLA and 6845 questions

Rob has posted a comprehensive manual which is enough to reimplement the functionality from. I believe hoglet reimplemented it in a project.
by cmorley
Sat Mar 14, 2020 3:16 pm
Forum: upcoming and recent events & exhibitions
Topic: ABUG Cambridge Booking Thread - May 15-17th 2020
Replies: 35
Views: 1273

Re: ABUG Cambridge Booking Thread - May 15-17th 2020

Hi Jason,
Can you please pencil me in for Saturday only no kit too?
Thanks,
Chris
by cmorley
Wed Mar 11, 2020 3:58 pm
Forum: software: other
Topic: puppeh's GCC6 for 6502
Replies: 27
Views: 4533

Re: puppeh's GCC6 for 6502

Did anyone have a fork of this, 'tis gone :( https://github.com/puppeh He changed his github handle to itszor. https://github.com/itszor/gcc-6502 I've been using the GCC8 branch & that is quite good. It would be even better if indexing & pointers were handled better - at the moment they produce a l...
by cmorley
Sun Mar 08, 2020 6:15 pm
Forum: projects
Topic: BCP: a BBC Micro printed circuit design program
Replies: 52
Views: 4221

Re: BCP: a BBC Micro printed circuit design program

julie_m wrote:
Sun Mar 08, 2020 4:24 pm
There is no crunching required, as it's just enough BASIC for the embedded assembler and a variable export dance. Anyway, my code is far too beautiful to spoil in such a fashion!
Until you run out of memory ;)
by cmorley
Sun Mar 08, 2020 3:10 pm
Forum: projects
Topic: BCP: a BBC Micro printed circuit design program
Replies: 52
Views: 4221

Re: BCP: a BBC Micro printed circuit design program

What are you editing the code on? I do my BASIC work on a PC with lots of comments... then send to a B for testing via the serial port. Last stage is to crunch it before release. Since the original is still on the PC in verbose form it makes editing & refactoring a breeze. :)
by cmorley
Sun Mar 08, 2020 10:33 am
Forum: hardware
Topic: Today I overclocked my A3010
Replies: 427
Views: 36145

Re: Today I overclocked my A3010

I then re-fitted the new RAM and... Mode 33 worked. So, although the machine was stable and everything worked yesterday other than the mode change it looks like there was a bad connection. Very strange. Now to try the overclock again. Can you repeat the game test before you try the overclock? Do yo...
by cmorley
Sat Mar 07, 2020 9:57 pm
Forum: hardware
Topic: Today I overclocked my A3010
Replies: 427
Views: 36145

Re: Today I overclocked my A3010

If it goes wrong on a 4MB A4000 and a 4MB A3010 in the same way but worked on a 2MB(?) A4000 then that would hint at a software bug.
by cmorley
Sat Mar 07, 2020 1:48 pm
Forum: hardware
Topic: Open source A3020 RAM
Replies: 57
Views: 3070

Re: Open source A3020 RAM

stephen_usher wrote:
Sat Mar 07, 2020 12:12 pm
To make it (FAR) easier to fit them I opened the ZIP memory connectors by poking my oscilloscope probe into the holes, widening the contacts just enough.
Huh... good idea.
by cmorley
Fri Mar 06, 2020 9:04 pm
Forum: for sale / freebies
Topic: For Sale: A3020/A4000 & A5000 overclockable RAM
Replies: 21
Views: 1478

Re: For Sale: A3020/A4000 & A5000 overclockable RAM

Everyone should have their RAM now (or at least on the way for myelin).
by cmorley
Wed Mar 04, 2020 8:43 am
Forum: hardware
Topic: New SCSI Host Adaptor
Replies: 40
Views: 905

Re: New SCSI Host Adaptor

I think Ken's work is well within the licenses. Except ironically the method for crediting Simon - including Simon's logo kinda implies endorsement which is banned by the CC license Simon linked.

Keep up the good work Ken.
by cmorley
Mon Mar 02, 2020 7:23 pm
Forum: general
Topic: Today I received.....
Replies: 5708
Views: 491867

Re: Today I received.....

LordVaderUK wrote:
Mon Mar 02, 2020 1:02 pm
A very exciting package from @marcusjambler...
Spare keyswitches for an Elk! Nice :D
by cmorley
Sat Feb 29, 2020 5:36 pm
Forum: hardware
Topic: Open source A3020 RAM
Replies: 57
Views: 3070

Re: Open source A3020 RAM

Memory fitting As per Mark's notes earlier in this thread then getting good access to your motherboard is essential to see what you are doing. 1. LINK31 pin 1-2 2. Remove LINK32 3. Insert modules (be careful) 4. Connect wire from LINK32 pin on module to LINK32 pin2 on the A3020/A4000 When inserting...
by cmorley
Sat Feb 29, 2020 1:26 pm
Forum: hardware
Topic: BBC B 32K - Incorrect characters displayed on screen
Replies: 23
Views: 688

Re: BBC B 32K - Incorrect characters displayed on screen

RAM fault (bit 1 of the "upper" bank of memory) or a problem with the Teletext chip or connection to it.

Do you get any graphical corruption in a graphics mode? Change to mode 0 - are there missing pixels or spurious pixels?
by cmorley
Sat Feb 29, 2020 1:24 pm
Forum: introduce yourself
Topic: Hello from Manchester
Replies: 8
Views: 264

Re: Hello from Manchester

Welcome! :D
by cmorley
Sat Feb 29, 2020 10:57 am
Forum: wanted
Topic: MegaRom 3.5
Replies: 8
Views: 212

Re: MegaRom 3.5

Yes. There is a sales thread.

If you want to solder the adapter yorself I can throw in the adapter PCB for free. If you want a fully assembled adapter ready to go I can do that too.

Chris
by cmorley
Sat Feb 29, 2020 10:32 am
Forum: wanted
Topic: MegaRom 3.5
Replies: 8
Views: 212

Re: MegaRom 3.5

I did this MOS switcher which uses my USB programmable EPROM module. A couple of forum members have them.
by cmorley
Thu Feb 27, 2020 8:38 pm
Forum: for sale / freebies
Topic: For Sale: A3020/A4000 & A5000 overclockable RAM
Replies: 21
Views: 1478

Re: For Sale: A3020/A4000 & A5000 overclockable RAM

Boards are ready for stardot users. I have PM'ed everyone on the list.
by cmorley
Thu Feb 27, 2020 6:01 pm
Forum: hardware
Topic: Open source A3020 RAM
Replies: 57
Views: 3070

Re: Open source A3020 RAM

There:
Photo0900.jpg
Much better! It is nice and easy to remove the RAM now.
by cmorley
Thu Feb 27, 2020 3:42 pm
Forum: hardware
Topic: Open source A3020 RAM
Replies: 57
Views: 3070

Re: Open source A3020 RAM

They are officially horrible to remove from the ZIP sockets! The sockets really grip the 39 pins - you have to pry between the socket and the pin headers to get them out without damaging the pins. Lots of patience required. I am going to swap the ZIP sockets on the project sponsor's A4000 for turned...
by cmorley
Mon Feb 24, 2020 7:26 pm
Forum: for sale / freebies
Topic: For Sale: A3020/A4000 & A5000 overclockable RAM
Replies: 21
Views: 1478

Re: For Sale: A3020/A4000 & A5000 overclockable RAM

The RAM arrived today. I will build up forum member's orders this week. I'll PM everyone on the list Wed/Thu.

If you are not on the list and want RAM then tell me ASAP.
by cmorley
Sun Feb 23, 2020 8:03 pm
Forum: other vintage computer hardware, software and games
Topic: 27C400/800/160/320 emulator/ROM switcher
Replies: 31
Views: 2465

Re: 27C400/800/160/320 emulator/ROM switcher

At the last ABUG I moved the ROM switch input on Tom's Master from the CPU (pin 40) to pin 13 of IC 19. This allows the module to hold the Master in reset under control from the USB serial link. IC14 (CPU) pin 40 would still work but you'd be shorting the output of IC39 pin 1 to ground which isn't t...
by cmorley
Wed Feb 19, 2020 7:54 am
Forum: upcoming and recent events & exhibitions
Topic: RISC OS South West Show Saturday 22nd February 2020
Replies: 16
Views: 1046

Re: RISC OS South West Show Saturday 22nd February 2020

RobC wrote:
Tue Feb 18, 2020 6:52 pm
I'll only be bringing one M128 so there should be enough space for three other setups.
I will bring a model B then. I'll aim for 9ish arrival as well.