Search found 8186 matches

by hoglet
Mon Jun 17, 2019 6:08 am
Forum: acorn atom and system
Topic: Interrupts on the AtomFPGA
Replies: 1
Views: 46

Re: Interrupts on the AtomFPGA

In AtomFpga_Atom2K18, the bus_irq_n signal is connected directly to the irq_n input of AtomFpga_Core: https://github.com/hoglet67/AtomFpga/blob/143b32de/src/xilinx/AtomFpga_Atom2K18.vhd#L378 Inside AtomFpga_Core it's combined with the irq_n output of the internal 6522, then connected to the CPU. htt...
by hoglet
Sun Jun 16, 2019 6:56 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 173
Views: 4447

Re: Atom Video to HDMI Adapter

Anyway it works - I've only tried it so far on my spare 2K Atom. Really good picture but so far can only get limited colours on the second palette (image attached), not sure why at this point but I wonder about a dry joint somewhere. RV2 doesn't seem to do much, but the sync seems rock solid whatev...
by hoglet
Sat Jun 15, 2019 5:23 pm
Forum: acorn atom and system
Topic: memory expansion
Replies: 23
Views: 272

Re: memory expansion

roland wrote:
Sat Jun 15, 2019 5:18 pm
There are also solutions that the FDC controller (8271) is moved to #BC48 so you have both 32k and FDC.
In my view this is the most logical thing to do.

Many of Kees' latest game conversions require RAM at #0Axx, otherwise they fail to run.

Dave
by hoglet
Fri Jun 14, 2019 4:39 pm
Forum: acorn atom and system
Topic: 2AtomFPGA - successor of Yarrb
Replies: 17
Views: 293

Re: 2AtomFPGA - successor of Yarrb

Then let's skip the AtoMMC and the EEPROM on this board and use the small EEPROM. One possible advantage of the parallel EEPROM is that it can be reprogrammed in software. But that is dangerous if it goes wrong. It's been possible on existing RamRom boards, and the FLASH command even exists in the ...
by hoglet
Fri Jun 14, 2019 2:48 pm
Forum: acorn atom and system
Topic: 2AtomFPGA - successor of Yarrb
Replies: 17
Views: 293

Re: 2AtomFPGA - successor of Yarrb

My concern is that you also need a programmer for that microcontroller. That's s good point... Charlie put a lot of effort into the boot loader for the PIC that allows for the reprogramming of the main FLASH. The AVR AtoMMC doesn't have that capability yet. Is that (psysicaly) the same SPI EEPROM w...
by hoglet
Fri Jun 14, 2019 11:46 am
Forum: acorn atom and system
Topic: 2AtomFPGA - successor of Yarrb
Replies: 17
Views: 293

Re: 2AtomFPGA - successor of Yarrb

Roland, I just tried a small experiment. I hacked a version of AtomFpga, removing a lot of stuff, until I ended up with just: - the 6502 section - the AtoMMC section - the Atom2K15 RamRom section - an optional SID section With the SID disabled, this uses ~90% of a XC3S200A and routes successfully. W...
by hoglet
Fri Jun 14, 2019 7:02 am
Forum: acorn atom and system
Topic: 2AtomFPGA - successor of Yarrb
Replies: 17
Views: 293

Re: 2AtomFPGA - successor of Yarrb

Hi Roland, This looks like a fun project. A couple of thoughts about your choice of FPGA - the XC3S50A. - The AVR version of AtoMMC needs 4KB of RAM and 20KB of ROM. So a total of 24KB. The XC3S50A only has 6KB of internal block RAM, so it's not going to fit. It's probably also not going to fit in t...
by hoglet
Thu Jun 13, 2019 4:10 pm
Forum: hardware
Topic: Big Box of Stuff
Replies: 33
Views: 2127

Re: Big Box of Stuff

Any chance of a scan of the Catalogue from 1987 too? I'm curious as to what boards were being promoted at that time, especially whether there were different CU-Graph boards for monochrome/colour. Here's a scan of the May 1987 Control Universal Catalogue: https://archive.org/details/ControlUniversal...
by hoglet
Wed Jun 12, 2019 8:34 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 656
Views: 53004

Re: ICE T65/Z80/6809

bprosman wrote:
Wed Jun 12, 2019 7:22 pm
Sure please contact me via a private message and I’ll send you one.
Tom won't be able to send a PM yet. Could you possibly send him your email address?
by hoglet
Wed Jun 12, 2019 2:52 pm
Forum: hardware
Topic: Proposed: "The Ultimate Electron Upgrade"
Replies: 367
Views: 23062

Re: Proposed: "The Ultimate Electron Upgrade"

With regards to a company building the board, I had a UK company called Quick-tek make some double sided pcbs and solder the all the smd components including a FPGA chip. The board was sold to people into the Sinclair QL, called the Q68. The end result does look very good. Am I right that these boa...
by hoglet
Wed Jun 12, 2019 2:30 pm
Forum: hardware
Topic: Big Box of Stuff
Replies: 33
Views: 2127

Re: Big Box of Stuff

Pernod wrote:
Wed Jun 12, 2019 1:04 pm
Any chance of a scan of the Catalogue from 1987 too? I'm curious as to what boards were being promoted at that time, especially whether there were different CU-Graph boards for monochrome/colour.
I'll scan that tomorrow.
by hoglet
Wed Jun 12, 2019 2:29 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 656
Views: 53004

Re: ICE T65/Z80/6809

So which pads am I soldering the headers to? Starting from the top row? ...and so we're on the same page. Which side is the top of the GODIL? :) I think the 40-pin header is actually fitted centrally (i.e. there should be two unused pads above and two unused pad below, on each side). There are some...
by hoglet
Tue Jun 11, 2019 7:22 pm
Forum: hardware
Topic: Big Box of Stuff
Replies: 33
Views: 2127

Re: Big Box of Stuff

Thanks for those, all looks legible =D> I was hoping for a little more technical info in the CU-Graph manual, but it does explain how colours are selected so still very useful. I guess it's not the hardware manual. The only thing I spotted that might be of use was the listing on page 26 (the printe...
by hoglet
Tue Jun 11, 2019 6:59 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

Ah, bugger, is the owl logo really important? :( The Owl Logo is working fine for me, do you have a new issue? Hang on though &EE _will_ have been cleared at DA56 _before_ interrupts are enabled at DA77 so a well behaved interrupt routine should, if it uses JIM, set EE and FCFF back to 0 after they...
by hoglet
Tue Jun 11, 2019 5:55 pm
Forum: hardware
Topic: Big Box of Stuff
Replies: 33
Views: 2127

Re: Big Box of Stuff

Here are some quick scans, so you can see what's there: CUGraphPeripheralDriverAndCubeHiResUnit.zip TeletextVDUInterface.zip TeletextVDUInterfaceIssue2Schematic.pdf TeletextVDUInterfaceIssue5ASchematic.pdf Sorry for the page order in the CU Graph manual, it was easiest to remove the staples and use ...
by hoglet
Tue Jun 11, 2019 5:10 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

Mmm, are you sure the FDFE thing looks to happen _before_ the roms are catalogued no? (Not at my machine to check just now). The issue only happens on a soft break, because: - the ROM table (&2A1) is not explicitly cleared on soft break - it likely still has valid contents from prior to the soft br...
by hoglet
Tue Jun 11, 2019 3:45 pm
Forum: hardware
Topic: Big Box of Stuff
Replies: 33
Views: 2127

Re: Big Box of Stuff

Today I collected a big box of Beeb related books/manuals/documentation from an ex BBC Bristol chap who was downsizing. I know this was a few years ago but did all the Control Universal manuals ever get scanned? At the moment I'm specifically interested in the Teletext and CU-GRAPH manuals, but wou...
by hoglet
Tue Jun 11, 2019 2:35 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

If a bootable device wanted to operate on a number other than 0 it could always use the same trick (i.e. claim the break vector) and install a shim in memory to call later and (re)select its device after the service calls are finished I don't think that works, because the unrecognised interrupt ser...
by hoglet
Tue Jun 11, 2019 2:30 pm
Forum: acorn atom and system
Topic: YARRB [SOLD OUT]
Replies: 240
Views: 12180

Re: YARRB

A weird thing is that ctrl-g does not produce a beep, but sound does work. If I load a sound-producing title that runs for a short while I can hear plips and bloops. If I change JP4 from 1+2 to 2+3 ( wrong, I know! ) then ctrl-g works even though the machine is unstable. The Ctrl-G thing is interes...
by hoglet
Tue Jun 11, 2019 1:15 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

I was half tempted to rule the boot thing out but lets try the "deliberate select" and "device 0" out and if that works its a start! Yes, that does work in all the cases I've tried so far. I'm reasonably happy with this for now, so I've just pushed a new version. It would be nice to get rid of the ...
by hoglet
Tue Jun 11, 2019 12:45 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 173
Views: 4447

Re: Atom Video to HDMI Adapter

=D> =D> =D> =D> =D>
by hoglet
Tue Jun 11, 2019 12:25 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

I think your second fix might work in this case, but can &EE be guaranteed to always be set to &00 after reset? I don't see where in a soft reset that happens. OK, I found the place where ZP (including EE) is cleared. But what about existing devices that use this mechanism? There were one or two I ...
by hoglet
Tue Jun 11, 2019 12:18 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

I think your second fix might work in this case, but can &EE be guaranteed to always be set to &00 after reset?

I don't see where in a soft reset that happens.

Dave
by hoglet
Tue Jun 11, 2019 12:15 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

I think we crossed over, see what I said above. I'd been over enthusiastic pruning your vhdl, reenable the FCFF=FF owl enable and write FF to EE - simple and fits with the spec I'm not sure your earlier fix will work. Did you manage to test it? The crash happens before any of the Owl Reset Code eve...
by hoglet
Tue Jun 11, 2019 11:32 am
Forum: acorn atom and system
Topic: YARRB [SOLD OUT]
Replies: 240
Views: 12180

Re: YARRB

Hi Charlie, I spent a whole afternoon a few weeks ago trying to work out why my AtoMMC had stopped working. It coincided with a fair about of board plugging/unplugging as I was testing the Noise Killer board. It turned out the AtoMMC cable had been pierced by a sharp component lead where it passes u...
by hoglet
Tue Jun 11, 2019 11:26 am
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

Dominic, I've got to the bottom of the Owl Logo issue. What happens is the following: - Soft break is pressed - MOS reset code at &E364 starts running - MOS tests for interrupt during reset sequence by briefly enabling interrupts - An interrupt is taken (Music 5000 is asserting IRQ to enable the Owl...
by hoglet
Tue Jun 11, 2019 10:02 am
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

Dave, I'd be grateful for any feedback! I've done a bit of testing this morning, of the following configuration: - Master 128 - Internal Pi Co Pro running Egg Eater - DataCentre Issue 2 - reprogrammed with dcjimapi.jed from your github repository - Beeb 1MHz Bus FPGA Adapter with the latest Music 5...
by hoglet
Mon Jun 10, 2019 6:14 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 173
Views: 4447

Re: Atom Video to HDMI Adapter

That disc is covered in mould - I'd recommend not putting in a drive, as it will clog the heads.
by hoglet
Sun Jun 09, 2019 3:19 pm
Forum: hardware
Topic: 1MHz bus and JIM interoperability
Replies: 34
Views: 645

Re: 1MHz bus and JIM interoperability

I'll try to do some testing of the new CPLD this week.

Do feel free to remind me if it doesn't seem to have happened.

Dave
by hoglet
Sun Jun 09, 2019 11:12 am
Forum: upcoming and recent events & exhibitions
Topic: Dutch Techsat 2019
Replies: 36
Views: 1860

Re: Dutch Techsat 2019

I also would love to see some photos, and read some posts about the days activities.

Dave