Search found 174 matches

by Sniffer
Thu May 09, 2019 6:31 pm
Forum: 8-bit acorn hardware
Topic: Repair Invoice - Courier damage
Replies: 2
Views: 606

Re: Repair Invoice - Courier damage

So would like some advice on getting a repair invoice, or something to satisfy the insurance When you say insurance, do you mean the insurance premium you paid to the parcel courier? I had a very similar problem when I purchased a MFD for my boat. I organised the courier (Parcel2Go) and the seller ...
by Sniffer
Thu May 09, 2019 2:00 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Some success :) Socketed a replacement IC25 and Trickys rom is off and running. Well I spoke too soon. Having socketed a couple of ICs relating to my disk problem I thought I had fried IC28, leaving me back at sqaure one. However, I replaced the IC and it didn't resolve the issue, I still had a bee...
by Sniffer
Thu May 09, 2019 8:19 am
Forum: 8-bit acorn hardware
Topic: 64K to 128K upgrade
Replies: 49
Views: 6987

Re: 64K to 128K upgrade

For a full RAM count you want RAMCount.
How is this used? I can see it's not basic.
by Sniffer
Tue May 07, 2019 9:33 pm
Forum: 8-bit acorn hardware
Topic: 64K to 128K upgrade
Replies: 49
Views: 6987

Re: 64K to 128K upgrade

Sorry for the confusion.
Absolutely no problem, thanks for taking the time to check.
by Sniffer
Tue May 07, 2019 8:27 pm
Forum: 8-bit acorn hardware
Topic: 64K to 128K upgrade
Replies: 49
Views: 6987

Re: 64K to 128K upgrade

I thought L13 meant S13, don't know why! Now I know why I thought that. The post refers to L9, L11, L12, L15 or L18 but actualy means S9, S11, S12, S15 or S18, along the east of the board. So, is there an actual L13? I now think it does mean $13 which brings me back to my original question. Both pi...
by Sniffer
Tue May 07, 2019 8:16 pm
Forum: 8-bit acorn hardware
Topic: 64K to 128K upgrade
Replies: 49
Views: 6987

Re: 64K to 128K upgrade

In the original upgrade, one of the pin 20s is taken to L13, not S13?
My bad. I think I need to get this senility looked at :) I thought L13 meant S13, don't know why!
by Sniffer
Tue May 07, 2019 7:18 pm
Forum: 8-bit acorn hardware
Topic: 64K to 128K upgrade
Replies: 49
Views: 6987

Re: 64K to 128K upgrade

Yes, it is. You only need to do the bottom ones for 1 and 27. Ok, thanks fo that. Another question. With the original upgrade, one of the pin 20s is taken to S13(south), which is fine. With your adaptation (over at https://stardot.org.uk/forums/viewtopic.php?f=3&t=16789 , you suggest the newly adde...
by Sniffer
Tue May 07, 2019 4:37 pm
Forum: 8-bit acorn hardware
Topic: 64K to 128K upgrade
Replies: 49
Views: 6987

Re: 64K to 128K upgrade

Please ignore my post above, I hadn't set things up correctly. User error once again!

Edited to say, I do have a question though. Why fold all the #1 & #27 pins up if you are to solder them all together? Surely it's easier to just fold up the bottom device's pins?
by Sniffer
Tue May 07, 2019 4:05 pm
Forum: 8-bit acorn hardware
Topic: 64K to 128K upgrade
Replies: 49
Views: 6987

Re: 64K to 128K upgrade

Old thread I know but I'm just having a play with this, trying to get my head around it, so as to do the upgrade. To "prove the concept" I made a provisional implementation with a 32K ROM with DFS and BASIC I have also created a rom with DFS & BASIC, concatenated together in a 32K ROM. BASIC on top ...
by Sniffer
Mon May 06, 2019 2:18 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

test for continuity on all the socketed ICs in the disc interface Thanks. I've done continuity checks, the first thing I always do, as even I can do that :) I'm on hold at the moment for a few days as I seem to have fried IC28 during a 'socketing' session. No damage to the board but the 74LS51 didn...
by Sniffer
Mon May 06, 2019 8:29 am
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

provide a reference Ok Mark, thanks. I'll try with pin10 on IC37 as a reference and I'll try as you suggest above with 0v/gnd and see what I can get. Thanks for the info. Edited to add image of pins 4,5&6 of IC77, using pin10 of IC37 as a reference (I hope). The first sub image is of pin10 IC37 onl...
by Sniffer
Sun May 05, 2019 11:46 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

If any of that doesn't match with what you've seen Well I am a little confused about what I've seen to be honest. Take the gate pins 4-6. Pin 4 has a mean of 4.24v, so high? Pin 5 has a mean of 11.2mv, so low? Meaning pin 6 should be high, yes? Pin 6 actually has a mean of 2.24v, which is below the...
by Sniffer
Sun May 05, 2019 11:34 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

Is it a known good DFS ROM (working in another machine) and a known good floppy drive (working in another machine) and correctly connected to the disc drive port (not 1MHz bus) and powered? Yep, the setup works well with other machines. It's an external PACE badged 5.25in external drive with good c...
by Sniffer
Sun May 05, 2019 9:06 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

Note, however, that they're active high on the 8271 itself So, to me, it looks like the beeb thinks I'm connecting to drive 1. On the 8271, pin 32 & pin 5 are both high on power on. Pins 2&6 are both high on power on. On doing a *cat, pin 2 remains high but pin 5 goes low. I only have one drive. Ed...
by Sniffer
Sun May 05, 2019 8:19 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

Are you using the correct disk filing system ROM (EPROM) chip for the disk controller that you have in use? Yes, I used the relevant roms. assume, from our discussions on the previous thread, that S9 is open now that you've fitted a FDC. Yes, I removed the jumper I had fitted and I did actually run...
by Sniffer
Sun May 05, 2019 6:41 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

Unlikely but one problem I had with a certain type of kit was the 'links' provided would not seat or stay/place nice in the IC sockets You mean the metal links between pins 1&4 and 9&12 when installing the 1770 upgrade? Yeah, they can be loose in the sockets but this problem exists with the 8271 as...
by Sniffer
Sun May 05, 2019 6:38 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Re: Can't access disc drive

These signals are active low Meaning when, for example, a *cat is issued, the pin would go low, otherwise stay high? So, on power up, pin 2 of the 8271 will be high? If so, this beeb conforms to that, in so far as on power up, pin2 is high, but then a *cat changes nothing, still high. Pressing esca...
by Sniffer
Sun May 05, 2019 5:13 pm
Forum: 8-bit acorn hardware
Topic: Can't access disc drive
Replies: 18
Views: 1337

Can't access disc drive

Having got a troublesome beeb booting ( https://stardot.org.uk/forums/viewtopic.php?f=3&t=17060&start=30 ), thanks to the guys here, I now want to access a memory test prog I have saved on disc. The trouble is, I can't access the drive. I have initially installed the 1770 disc upgrade but can't acce...
by Sniffer
Sun May 05, 2019 4:54 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Excellent! Good news. Yep, good news. As mentioned above, I might have ram issues so I intend to run a memory test prog that I have on disc (listing from this site) so I have installed the 1770 disc upgrade but can't access the attached drive. The setup is good, it works well with other beebs. *cat...
by Sniffer
Sun May 05, 2019 10:04 am
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Some success :) Socketed a replacement IC25 and Trickys rom is off and running.

I think I have some ram issues which I'll now look at but I just wanted to report the success =D>

Thanks guys.
by Sniffer
Sat May 04, 2019 10:44 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Did you perhaps knock the x10 switch by mistake? Sorry, yep. Here is IC29 11,12,13 again. IC29-11-12-13.png Firstly, check that the 5V and GND supplies for IC34 They're good. Then, could you use your scope to look at the values on pins 1-6 of IC34, please? IC 34, pins 1-6 in order; IC34-1-6.png Tha...
by Sniffer
Sat May 04, 2019 9:30 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Please probe pins 11, 12, and 13 of IC29, and show us what you see.
Sure. This was I think the first IC I replaced. Order 11,12,13.

SDS00006.png
by Sniffer
Sat May 04, 2019 8:18 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Could you please set your ‘scope to a more sensitive range and re-do the signal on pin 37 please. A photo with the waveform nearly filling the screen is best. Please bear in mind I'm a novice with a scope. The scope is not hooked upto a pc, the images are directly from the scope. SDS00005.png This ...
by Sniffer
Sat May 04, 2019 8:08 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Nothing changes with a known good cpu.
by Sniffer
Sat May 04, 2019 7:32 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Can you please post images of the waveform on the following pins: 37, 39 and 3. Sure. Inorder 3,37,39; 3-37-39.png When you said you'd swapped out all socketed components, did that include the CPU? Yes it did but I suspected a problem with this cpu so I bought one off Dave H, which is on it's way. ...
by Sniffer
Sat May 04, 2019 6:36 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Could you scope out the CPU's pins too Sure, pins 1 to 40 in order; 1 L 2 H 3 L 4 H 5 N 6 H 7 H 8 H 9 L 10 L 11 L 12 L 13 L 14 L 15 L 16 L 17 L 18 L 19 L 20 L 21 L 22 L 23 L 24 L 25 L 26 P 27 P 28 P 29 P 30 P 31 P 32 P 33 P 34 H 35 N 36 N 37 P 38 H 39 H 40 H Would you like images of the pulsing pins?
by Sniffer
Sat May 04, 2019 10:38 am
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Could you confirm each of those measurements with your scope?
Here's an image of pins 4 to 7 of IC6. No idea if it's what you wanted, as I freely admit, I'm not proficient with the scope.

IC6_P4-P7.png

If you were expecting something else, measurement wise, just say and I'l try and do it.
by Sniffer
Sat May 04, 2019 9:50 am
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

If that scope output is from measuring one of pins 3, 37 or 39 (the clock pins) on the CPU, then that's a good enough square wave to drive the CPU clock. CPU pin 37. Could you confirm each of those measurements with your scope? Will do. Can you confirm which ROM was/is in the OS socket for these te...
by Sniffer
Fri May 03, 2019 11:28 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Uused 10X probe setting. Still learning with this (any) scope.
by Sniffer
Fri May 03, 2019 10:21 pm
Forum: 8-bit acorn hardware
Topic: Non booting BBC/B Issue 7 - Continuous beep Mk 2
Replies: 43
Views: 2596

Re: Non booting BBC/B Issue 7 - Continuous beep Mk 2

Got the scope out, not a square wave in sight, though admittedly, I could be doing something wrong :)

Editted to add image (cpu clock);
SDS00001.png

Not sure if this means anything, will learn more in the morning.

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