Search found 1349 matches

by Pr0f
Mon Jun 17, 2024 8:16 am
Forum: General QL Chat
Topic: Announcement for RetCon 2024 in West London, Sat 15th June
Replies: 7
Views: 272

Re: Announcement for RetCon 2024 in West London, Sat 15th June

I think this is an excellent idea Martyn! The idea of an open network that would be usable with other Micros - love it. I think it would be good to have support for 'lesser devices' - enabling support for hardware interfaces - such as LCD display module, digital I/O and analog I/O - perhaps achievab...
by Pr0f
Fri Jun 14, 2024 8:38 am
Forum: Hardware
Topic: Announcing the new "Gold Card" - QIMSI Gold
Replies: 98
Views: 9474

Re: Announcing the new "Gold Card" - QIMSI Gold

I've only ever seen a Q40 for sale - so the rarity value alone would mean a reasonable price tag, but then you are getting a significant upgrade to a QL! A new 68060 design would probably need to use a PCI bus, which is becoming old technology now too, unless of course you go down the route of using...
by Pr0f
Thu Jun 13, 2024 9:34 pm
Forum: Hardware
Topic: 8302
Replies: 16
Views: 6423

Re: 8302

The code in the mister FPGA does just enough to 'mimic' a Microdrive interface, and provide a rudimentary seconds counter RTC, but don't be fooled - there is a lot that's not supported here - not sure if the QL network interface is implemented in the mister hardware? Certainly the serial port (trans...
by Pr0f
Thu Jun 06, 2024 4:42 pm
Forum: Software & Programming
Topic: 68K/OS "ROM" based disk attempt
Replies: 82
Views: 4155

Re: 68K/OS "ROM" based disk attempt

As per my previous post - the OE signal on the Eprom is active low - and on the QL PCB - and hence on the ROM socket - it's active high. You will need to invert the signal with a transistor or a logic gate. Easiest would be to use a BS170 mosfet - gate to the ROMOEH signal on the QL socket, Source c...
by Pr0f
Tue Jun 04, 2024 10:38 pm
Forum: Software & Programming
Topic: 68K/OS "ROM" based disk attempt
Replies: 82
Views: 4155

Re: 68K/OS "ROM" based disk attempt

It also makes me wonder if the 68K/OS can potentially access ROM disks at other possible ROM locations - such as at 10000 or 14000, or in the top 256K of space - from 0C0000h onwards.

Obviously dependant on any expansion cards or GC or SGC being present.
by Pr0f
Tue Jun 04, 2024 10:35 pm
Forum: Software & Programming
Topic: 68K/OS "ROM" based disk attempt
Replies: 82
Views: 4155

Re: 68K/OS "ROM" based disk attempt

would be handy to design a ROM port plugin cartidge with a switch or jumpers and a ZIF socket - for just such experiments :-)
by Pr0f
Tue Jun 04, 2024 8:00 am
Forum: Software & Programming
Topic: 68K/OS "ROM" based disk attempt
Replies: 82
Views: 4155

Re: 68K/OS "ROM" based disk attempt

The main issue from memory is that an Eprom has two pins OE and CE - these are both active low (when 0v, they are activated). On the 28 pin socket - the A15 address line is where you would normally find CE - so that will address the Eprom from 00000h to 07FFFh - which is the bottom 32K - no problem ...
by Pr0f
Mon Jun 03, 2024 9:46 pm
Forum: Software & Programming
Topic: 68K/OS "ROM" based disk attempt
Replies: 82
Views: 4155

Re: 68K/OS "ROM" based disk attempt

The original ROM's used by Sinclair are a pair - the "enable" line is active High on the 'top' 16K ROM and active Low on the 'bottom' 32K ROM, regardless of which socket you put them in - they will always work together - this is also why you can piggy back solder them and fit them in only ...
by Pr0f
Mon Jun 03, 2024 8:01 pm
Forum: Software & Programming
Topic: 68K/OS "ROM" based disk attempt
Replies: 82
Views: 4155

Re: 68K/OS "ROM" based disk attempt

I believe the ROM port actually addresses 64K, so from 00000H to 0FFFFH - ROMOEH is an enable high for any address in the lowest 64K - ROM cartridges use a logic gate to decode the top 16K and use it with ROMOEH to enable the Eprom / ROM chip in the ROM expansion port. So nothing to stop you doing 3...
by Pr0f
Sun Jun 02, 2024 9:55 pm
Forum: Software & Programming
Topic: 68K/OS "ROM" based disk attempt
Replies: 82
Views: 4155

Re: 68K/OS "ROM" based disk attempt

Are there specific types your programmer will work with?

What programmer is it?

I have a lot of Eprom's - just in the process of moving my 'man cave' - but if I have the type you need - I am happy to post some to you.