Fun things to do with an MC68EC020....

[Dave]

So, Nasta, here's what I've done:

Designed a crude "replacement" QL board that just retains everything the same as now, but SMD. I ignored the on-board RAM, microdrive and power circuitry. That cuts it down to 100x160mm. There are two 8Mx16 SRAMs, two 32kx16 flash chips holding the Minerva image, so it's 32-bits wide too. A 68EC020 @ 24MHz, and I'm adding provision for a 68882 so I can add an FPU later if it proves useful. It takes the existing custom logic, etc - all the socketed ICs from a BBQL just get moved across, and it can take a TF kbd i/f if needed, but it can handle membranes too. It has a roughed out floppy i/f and if I can get permission, there's room for the QubIDE components there too, though I'd like to re-implement that in SMDs and put a CF card adaptor on one edge, making the board a little larger. It uses an ATX power supply. It has two expansion ports but that's a squeeze.

As it stands, there's a chance I might evolve it enough to make a run and sell them. Given the cost of GC/SGC recently, I know the price would be attractive and they would sell well. My other business is going reasonably well, so I am finding an ever-increasing disposable income that I can add to my fundraising.

So, anyway, that's what I have been playing with.

[tofro]

Dave,
that really sounds like a story....

A replacement board that would fit into the original QL case with CF (and/or SD), 68020, Floppy interface at a reasonable price - I'd buy one, definitely. If the mass storage could re-use the space of the original micro drives, even better.

It used to be different - but nowadays, I guess, modern hardware can't just simply assume people will put it somewhere it fits (i.e., new case) - If it doesn't fit into the original QL's black box, I can just as well use an emulator.

I could very well live with the original video (some later upgrade, maybe?), but speed and modern mass storage capability is a must.

Tobias

[Dave]

I started the pastime (it's just a hobby project) in part because I only have a half dozen microdrive cartridges that haven't utterly failed. Of the four US QLs I recently received (the most evolved Samsung ones) only one had two working microdrives. It's fair to say microdrives are now an amusing historical side-note.

If I ever did anything with it, I would put the CF card reader on a platform PCB that would perfectly replace a microdrive. I'd just put the IDE interface on the board, and then people could choose none, one or both being CF slots.

[tofro]

It's fair to say microdrives are now an amusing historical side-note.

Right. Even un-used, brand new cartridges seem to have seen most of their lifespan now. Yesterday I played with my "new" MGG QL that was bought as new in 1990 as a spare and packed away for 20 years. The first cartridge I checked from that set already threw its felt pad at me.... I didn't dare to insert it.

Regards,
Tobias

[thorsinclair]

Hi Dave,
a hardware replacement motherboard that fits in the original case would just be perfect! You may can leave one microdrive in use in order to copy the old stuff on a SD card or floppy ... the other slot could always be used for the SD card (like Peter Graf's project). I remember that some months ago I read about a Ethernet card project which was more or less finished ... if this could inserted inserted besides USB and a digital video out in order to connect a good monitor it would just be perfect. If Nasta is helping you it's just great news ...

Fingers crossed by a potential buyer

Best,
Th

[dilwyn]

Hi Dave,
a hardware replacement motherboard that fits in the original case would just be perfect! You may can leave one microdrive in use in order to copy the old stuff on a SD card or floppy ... the other slot could always be used for the SD card (like Peter Graf's project). I remember that some months ago I read about a Ethernet card project which was more or less finished ... if this could inserted inserted besides USB and a digital video out in order to connect a good monitor it would just be perfect. If Nasta is helping you it's just great news ...

Fingers crossed by a potential buyer

My opinion is that there are two ways a "new" QL could go.

One is the all-singing all-dancing new QL in as compact a form and as advanced as reasonably possible.

The second is that a replacement QL motherboard of this type is done, which is purpose designed to fit in a QL case and keyboard. Although this was possible (with great effort) with an Aurora, I'm sure Nasta will agree it was really designed for a PC case type of rebuild.

With the current nostalgia level with retro computing, preserving as much of the original appearance of the system may be a way to go, and after all, in terms of design looks the QL is well known and generally well liked (computer in a keyboard). If there are enough QL cases around to achieve this of course.

Quite what hardware compatibility you go for is open to debate - personally I don't think microdrives are worth the effort (just network a QL to a QL2 for transfers if you really want).

So, here is what I'd like kept/added in a QL2:

Faster processor
Expanded memory - to Gold Card/Super Gold Card level at least.
Parallel port
Serial ports
Joystick ports
Ethernet (assuming Petri ever finished his card)
IDE interface for hard disk and/or compact flash adaptor
Flash memory (either compact flash as above or SD card)
Floppy disk connection
QL network
Enhanced video (higher resolution and colours and connection to modern monitors)
Sound (QLSSS)

Now that's asking a lot, but I can dream of a more modern QL which still looks like a QL. Oh, hang on, QPC2 already does much of this

[Dave]

Green means working/solved. Red means no way for me to do. Grey means it's coming.

Faster processor
Expanded memory - to Gold Card/Super Gold Card level at least.
Parallel port
Serial ports
Joystick ports
Ethernet (assuming Petri ever finished his card)
IDE interface for hard disk and/or compact flash adaptor
Flash memory (either compact flash as above or SD card)
Floppy disk connection
QL network
Enhanced video (higher resolution and colours and connection to modern monitors)
Sound (QLSSS)

I am working with Petri to try to get his ethernet design into many peoples' hands, but he is very busy with work right now, so it will just have to wait. Extended video would require the equivalent of a SuperHermes for video, and I just don't see anyone stepping forward to design that. There's a lot of time and risk involved for almost certainly no financial reward.

[Dave]

Here's where I'm at:

68EC020: 24MHz or 8MHz switchable. Could as easily use a 68020 if more address lines were desired (more memory)
Re-uses all QL custom logic - supports superHermes
Video RGB output
QL on-board serial and joystick ports replicated
IDE via on-board QubIDE with SMD logic
Sandy SQB parallel and floppy i/f on-board with SMD logic
16MB 32-bit RAM (not all wired in) if used with an EC020 - up to 4GB with 68020
128k 8-bit RAM
2k 8-bit NVRAM
Battery backed clock
Sound (but with everything over 12 kHz filtered out)
Two expansion ports
Minerva 1.97 (unmodified - can you help? You'd get one of these to help your testing!)
Telecoms power socket (not ATX)

Coming:
Ethernet
QL network

Never coming:
microdrive support
ROM port - with flash memory, this unit can simply have the ROM image stored on-board. A "ROM management system" will need to be written to allow multiple ROMs to be stored and enabled/disabled, etc. TK2, Sandy floppy/parallel are currently on-board.

I rejigged the QL expansion port. Everything in the DIN connector is 100% compatible, but I put extra address lines on the R, G and B pins since nobody ever used those. I have now decided that is a bad idea, because if anyone produces a video card it might want those lines to feed video back. So I am working on using a small secondary connector alongside the original one.

Right now it's gross. All prototype with wire-wrap and a couple of home-etched boards of stable areas. Right now, in spare time I am slowly turning this into a 4-layer PCB design. I'll get two or three made and test it to see how it works, how noisy or marginal any areas are then rework those areas.

Please understand, there's nothing elegant about this design at all. It's an '020 shoehorned into a QL with a bunch of memory and absolutely no performance enhancements whatsoever. No shadowed video, no copying of ROMs to fast RAM (thought ROM is wide and fast) and the speed of this, while reasonable, is not up to SGC standards.

My mental picture of this, if it goes forward, is as follows:

Remove the QL mainboard and microdrives. Remove all custom logic from the QL and put it into the QL2 board. Mount a telecoms PSU where the heatsink used to be. Power switch in network hole (perfect fit) and IEC socket adjacent. A PCB would go across the two microdrive slots, each containing a CF card slot. An IDE ribbon cable from the underside of the board to the IDE on the QL2. I haven't found a way to fit a single floppy inside the case without huge compromises, so the flp cable would go to a panel in the ROM port, and external drives can plug in there. Serial would be 9-pin DSUB, likewise joystick/ctrl ports, using the existing locations with a little rework for non-Samsung QLs. QL monitor output currently uses an 8-pin DIN, but I might use a VGA converter and put a standard VGA socket on it.

IMPORTANT REMINDER!
I've already had a couple of people email me asking when they can buy one, etc. I appreciate the interest, which is why I am keeping everyone informed. However, please remember that at the moment this is a purely personal project, a hobby activity. If I can get the design to a place where I think it could be made, work reliably for 30 years and not be awful, I'd happily make a batch. However, I am FAR from that place.

The primary purpose of this thread is to keep everyone in the loop and see what assistance/help I can get. I need help with Minerva. I need help with the QL video if there's to be an improvement there, which I consider the major weakness of this design.

Also, I'm debating designing and selling the CF/microdrive adaptors for those who already have a QubIDE, but I have no idea how many would sell. I don't know how many QubIDEs there are in regular use, and how many of those are in a QL case not a PC case.

ALSO!

One person suggested something I am thinking through - why bother struggling with the CPU when the GC/SGC already do it better? Why not just design a QL replacement PCB anyway? That would be a lot cheaper and simpler, wouldn't it? I am thinking on that idea too, but they could share a common PCB for both ideas.

So, that's my thought process right now.

[Dave]

And I forgot to mention, it will have a socket for a 68882, so floating point on it would be blindingly fast, if support is compiled in.

[dilwyn]

And I forgot to mention, it will have a socket for a 68882, so floating point on it would be blindingly fast, if support is compiled in.

I'm pretty pleased that, apart from the video and FPU, I aimed more or less where you were headed with this!

As far as FPU support goes, there are articles and code from George Gwilt and Simon Goodwin on my website at http://www.dilwyn.me.uk/docs/asm/index.html although I have no idea how suitable these would be. You'd probably need to ask George about use of the code.