Search found 905 matches

by IanS
Sun Jun 23, 2019 10:11 am
Forum: software
Topic: New demo - Horizon
Replies: 5
Views: 195

Re: New demo - Horizon

Looks good, and ran OK on my R140/ARM3/4MB.
by IanS
Tue Jun 18, 2019 8:38 pm
Forum: hardware
Topic: Formatting SD/CF cards for use on RISC OS 3.1
Replies: 87
Views: 21008

Re: Formatting SD/CF cards for use on RISC OS 3.1

Hopefully these links work to the photos: https://photos.app.goo.gl/g7fNaU1AYSoww4C46 https://photos.app.goo.gl/6UurtGvLFZnBuvx57 If I do *HELP IDEFS it tells me it's IDE 3.01 (02 May 1994) (C) Alsystems Unfortunately I don't seem to have !HForm on a floppy or on the hard drive, although I do vague...
by IanS
Tue Jun 18, 2019 7:46 pm
Forum: hardware
Topic: Formatting SD/CF cards for use on RISC OS 3.1
Replies: 87
Views: 21008

Re: Formatting SD/CF cards for use on RISC OS 3.1

Have you got a picture of the interface? I didn't think Alsystems did a 8-bit interface. It may be someone elses board with a Power-tec ROM. Have you get a copy of !Hform on a floppy that you can run on the A3010? It may help in the identification of the drive. Run it and see if it recognises the dr...
by IanS
Sun Jun 16, 2019 4:27 pm
Forum: acorn atom and system
Topic: memory expansion
Replies: 27
Views: 451

Re: memory expansion

Yes, the FDC only needs the first four addresses as it has only two address input lines (A0 and A1). Does it fully decode the other address lines, or does it respond for a larger block?. Do the addresses that the FDC drives the bus repeat? Are #0A00 and #0A04 the same? EDIT: Looking tha the circuit...
by IanS
Sun Jun 16, 2019 3:46 pm
Forum: acorn atom and system
Topic: memory expansion
Replies: 27
Views: 451

Re: memory expansion

Where is the equation for OE? You can enable writing to the RAM for the whole 32K, but the enabling the chip for read, so two devices don't try to output at the same time onto the bus is the important bit.
by IanS
Sat Jun 15, 2019 6:22 pm
Forum: acorn atom and system
Topic: memory expansion
Replies: 27
Views: 451

Re: memory expansion

I was thinking of doing something similar on one of my Atoms, and had assumed I'd just use A15 (low) as the RAM CE, so it covered the whole lower 32K (where it's enabled by the IC5 output) That was my first attempt, but wouldn't this rule out other expansions like the FDC? I was planning it for an ...
by IanS
Sat Jun 15, 2019 1:53 pm
Forum: acorn atom and system
Topic: memory expansion
Replies: 27
Views: 451

Re: memory expansion

Take out 2114's and IC6, add pull-ups to the inputs to IC5, so the offboard RAM is enabled for the internal address space? I was thinking of doing something similar on one of my Atoms, and had assumed I'd just use A15 (low) as the RAM CE, so it covered the whole lower 32K (where it's enabled by the ...
by IanS
Fri Jun 14, 2019 5:55 pm
Forum: for sale / freebies
Topic: FS: 16-bit IDE podules - SOLD OUT.
Replies: 15
Views: 772

Re: FS: 16-bit IDE podules - SOLD OUT.

I'm hoping to have a few more built for the weekend of the Abug event. If there are any left after that weekend, I'll list them here.
by IanS
Mon Jun 10, 2019 9:45 pm
Forum: upcoming and recent events & exhibitions
Topic: ABUG Cambridge 28th - 30th June 2019 BOOKING THREAD - NOW FULL
Replies: 155
Views: 5238

Re: ABUG Cambridge 28th - 30th June 2019 BOOKING THREAD - NOW FULL

JudgeBeeb wrote:
Mon Jun 10, 2019 8:49 pm
Would it be alright if Sharon comes along to this one? I know we are tight for space; but she asked if she could come along without any prompting.
I can't speak in an official capacity, but as you've booked a full table, I can't see it being a problem.
by IanS
Sun Jun 09, 2019 12:48 pm
Forum: hardware
Topic: New econet setup
Replies: 88
Views: 2567

Re: New econet setup

As Daniel says the 10nF isn't polarised.

The other is marked.
caps.PNG
So the way you have it in the photo is correct.
by IanS
Sat Jun 08, 2019 11:57 pm
Forum: programming
Topic: VDU ?
Replies: 21
Views: 538

Re: VDU ?

It doesn't say 82 mod 02. The 8202 is a two byte value, or a word. The MOD(ulo) and DIV are the remainder of a division and integer division. Which in this case are just a way of getting the two bytes one by one. 8202 (base 10) is &200a (base 16). MOD 256 will get you the low byte (&0a) , DIV 256 w...
by IanS
Sat Jun 08, 2019 11:45 pm
Forum: programming
Topic: VDU ?
Replies: 21
Views: 538

Re: VDU ?

It doesn't say 82 mod 02. The 8202 is a two byte value, or a word. The MOD(ulo) and DIV are the remainder of a division and integer division. Which in this case are just a way of getting the two bytes one by one. 8202 (base 10) is &200a (base 16). MOD 256 will get you the low byte (&0a) , DIV 256 wi...
by IanS
Sat Jun 08, 2019 11:03 pm
Forum: programming
Topic: VDU ?
Replies: 21
Views: 538

Re: VDU ?

If the <numeric> is followed by a semicolon ; then the value is a little-endian word from 0 to 65535 inclusive. It is broken down into two ASCII values; first the word value MOD 256, then its value DIV 256. This word syntax is useful for graphics coordinates or for crunching BASIC programs. From ht...
by IanS
Sat Jun 08, 2019 10:28 pm
Forum: hardware
Topic: A4000 issues
Replies: 2
Views: 121

Re: A4000 issues

When the floppy drive light flashes, what error is is giving - https://www.retro-kit.co.uk/page.cfm/co ... re-errors/ (use the decoder on the right-hand side)

I don't think the A4000 supports anything higher than RISC OS 3.11 (or 3.19 in German).
by IanS
Fri Jun 07, 2019 6:38 pm
Forum: hardware
Topic: A5000 memory module.
Replies: 2
Views: 144

Re: A5000 memory module.

No, they were unique to the A5000.
by IanS
Thu Jun 06, 2019 8:00 pm
Forum: hardware
Topic: A5000 Power Supply Circuit Diagram
Replies: 21
Views: 336

Re: A5000 Power Supply Circuit Diagram

I don't think I've ever seen a circuit diagram for any of the Arc machine power supplies. The A5000 (without expansions or HD) will happily run on just +5V if you want to check that it is just the power supply at fault. Without any add-ons I think it uses under an amp, shouldn't be hard to find a su...
by IanS
Thu Jun 06, 2019 4:29 pm
Forum: hardware
Topic: IDE interfaces - hardware details
Replies: 112
Views: 5695

Re: IDE interfaces - hardware details

Ian, what is the purpose of the connection from the Gal to pin 31 (F_prgm or WE#) of the rom,does it simply set it high? I plan to use a 27512 as I have some available, with just a Zidefs rom programmed. If I link pin 32 of the socket to pin 28 of the 27512 for Vdd all else is pin compatible but ob...
by IanS
Wed Jun 05, 2019 10:58 pm
Forum: hardware
Topic: BBC micro RGB to scart problems (help/ suggestions)
Replies: 19
Views: 429

Re: BBC micro RGB to scart problems (help/ suggestions)

I suspect he's refering to the cable. It should be possible to feed a signal from the beeb to the tv to make it switch to RGB mode. A lot of cables use a simple diode and capacitor in the scart connector to generate the switching signal from the sync connection, but it's not always reliable. If ther...
by IanS
Mon Jun 03, 2019 6:09 pm
Forum: hardware
Topic: IDE interfaces - hardware details
Replies: 112
Views: 5695

Re: IDE interfaces - hardware details

Stevetuc wrote:
Mon Jun 03, 2019 5:01 pm
I have ordered a batch of podule_ide_a3000_v2 and will have 4 pcbs free if anyone is interested at 12gpb each inc postage
Is that assembled, or just a blank PCB?

I should upload the v3 details, though it is a bit fiddly with the surface mount parts.
by IanS
Sun Jun 02, 2019 10:28 am
Forum: software
Topic: Trying to format hard drive
Replies: 9
Views: 281

Re: Trying to format hard drive

KarateEd wrote:
Sun Jun 02, 2019 4:22 am
I see the 37 Boot disk is no longer available?
Use the universal boot instead.
by IanS
Sat Jun 01, 2019 10:09 pm
Forum: hardware
Topic: Page ROM/RAM
Replies: 19
Views: 491

Re: Page ROM/RAM

You seem to simulating a latch, doesn't the chip have them built in?

The 22V10 I use for IDE podules has a dedicated Clock pin, so I just define the latched signals as Q0.D = D0. I assume you'd have to define the clock using .CK. e.g. C0.CK = E (untested).
by IanS
Sat Jun 01, 2019 9:50 pm
Forum: hardware
Topic: Can you identify this board
Replies: 4
Views: 197

Re: Can you identify this board

Econet (without hardware collision detection)
by IanS
Sat Jun 01, 2019 7:52 pm
Forum: hardware
Topic: Page ROM/RAM
Replies: 19
Views: 491

Re: Page ROM/RAM

Suprised you can't put the latch (74ls75) in the CPLD.
by IanS
Thu May 30, 2019 9:18 pm
Forum: software
Topic: A3000 Joyport
Replies: 1
Views: 122

Re: A3000 Joyport

Without uniboot (or other boot file setup), nothing is run automatically. You could look at using the desktop icon to create a !boot file, but it's a bit messy. Middle click on the Acorn icon on the far right end of the and pick the desktop boot option. Open the resulting file in !Edit to see what s...
by IanS
Thu May 30, 2019 9:14 pm
Forum: software
Topic: Trying to format hard drive
Replies: 9
Views: 281

Re: Trying to format hard drive

!hform is on the utilities disk - http://riscos.com/ftp_space/370/index.htm

Do you have a way of getting that onto a floppy disk?
by IanS
Mon May 27, 2019 1:49 pm
Forum: hardware
Topic: CompactFlash card on Castle A30x0 IDE Mini Podule
Replies: 30
Views: 904

Re: CompactFlash card on Castle A30x0 IDE Mini Podule

Did you use the boot floppy? https://stardot.org.uk/forums/viewtopic.php?f=16&t=11247#p140562 I had no success with the boot floppy. I found a drive that works with the Castle card without the wizzo modules(I don't have any working 2.5" drives, so it was a 3.5" drive). I assumed that wizzo would no...
by IanS
Mon May 27, 2019 12:19 pm
Forum: off-topic
Topic: ATF22V10C vs GAL22V10D
Replies: 16
Views: 268

Re: ATF22V10C vs GAL22V10D

There appears to have been some issues with programming the Atmel 22V10 parts on the TL866II in the past. Could it be the part is not programmed correctly. Is there a later version of the software available? When you don't get the signal you expect on a pin, have you tried probing all the other outp...
by IanS
Wed May 22, 2019 10:07 pm
Forum: hardware
Topic: CompactFlash card on Castle A30x0 IDE Mini Podule
Replies: 30
Views: 904

Re: CompactFlash card on Castle A30x0 IDE Mini Podule

Did we confirm if wizzo does or doesn't help with the castle mini podule. I didn't get chance to check at the weekend.
by IanS
Wed May 22, 2019 8:12 pm
Forum: upcoming and recent events & exhibitions
Topic: ABUG Cambridge 28th - 30th June 2019 BOOKING THREAD - NOW FULL
Replies: 155
Views: 5238

Re: ABUG Cambridge 28th - 30th June 2019 BOOKING THREAD

Will there be anybody bringing an Econetted Atom? I've got a list of bugs with Atom support for SoftMDFS, so it would be useful to have some live systems available for testing. I'lll bring at least one. I plan to either get the Atom software archive running on Econet and bring it with me, or bring ...
by IanS
Tue May 21, 2019 10:01 pm
Forum: hardware
Topic: CompactFlash card on Castle A30x0 IDE Mini Podule
Replies: 30
Views: 904

Re: CompactFlash card on Castle A30x0 IDE Mini Podule

EDIT: Couple of hardware notes -- Photos of the hardware -- http://www.computinghistory.org.uk/det/47496/Castle-A30x0-IDE-Interface/ and http://chrisacorns.computinghistory.org.uk/32bit_UpgradesA2G/Castle_A30x0IDE.html From left to right in the Chris's Acorns photo, the parts are: 74HC245, 74HC573,...