New QL user & owner

[QLvsJAGUAR]

So the question is, can this be made to work to any degree without the original 8000 ROM? Lacking some features, but some kind of stable environment?

The 32KB ($0000 and $4000) of "13-2-84" are starting up in qlay, but stop at the memory test pattern. It looks like most of QDOS is in the third 16KB.

I assume the content of TUTOR C000 is just a some dozends or few hundreds bytes. At those days the small team at Sinclair Research had no time to write huge test programs, they did not even time to write the code for all planned features.

[M68008]

So the question is, can this be made to work to any degree without the original 8000 ROM? Lacking some features, but some kind of stable environment?

I think the ROM contains the entire SuperBASIC, but only a small part of QDOS, so while BASIC programs could be made to work, a lot would be broken. For example, graphics commands simply check the parameters and call the missing part of QDOS to do the heavy lifting.
I've started an experiment, so stay tuned.

[M68008]

Here is what I got after two days of work. I concatenated the ROM with the JS ROM into a 80 KB file, then stitched the two together by fixing the main jumps from one to the other.

The resulting Franken-ROM is a bit unstable since some data structures are defined in the BASIC ROM, but used in the JS that assumes a slightly different format.
For example, microdrives and graphics command like LINE are not currently working. The problem with graphics is that the BASIC ROM also contains the code to open a CON channel (the original ROM must have been a full QL QDOS+BASIC like later ROMs, just with the order of code in the ROM swapped: BASIC first, QDOS second), but that code doesn't set the SCALE factor in the channel, and that is needed by JS. The ROM does contain a SCALE BASIC command, maybe scaling just worked in a different way back then.

Other approaches would be possible (e.g. only use the SuperBASIC portion from the ROM, so that the rest of the OS is consistent, and use the older PM ROM instead of JS), but in any case the result will not be equivalent to the original: Components like most of the CON driver would be from a different ROM and there is no way to know for sure how it originally looked without recovering the missing ROM at $8000.

QL_screen_000.png (530 Bytes) Viewed 953 times

QL_screen_010.png (1.36 KiB) Viewed 953 times

[Chr$]

Here is what I got after two days of work. I concatenated the ROM with the JS ROM into a 80 KB file, then stitched the two together by fixing the main jumps from one to the other.

The resulting Franken-ROM is a bit unstable since some data structures are defined in the BASIC ROM, but used in the JS that assumes a slightly different format.
For example, microdrives and graphics command like LINE are not currently working. The problem with graphics is that the BASIC ROM also contains the code to open a CON channel (the original ROM must have been a full QL QDOS+BASIC like later ROMs, just with the order of code in the ROM swapped: BASIC first, QDOS second), but that code doesn't set the SCALE factor in the channel, and that is needed by JS. The ROM does contain a SCALE BASIC command, maybe scaling just worked in a different way back then.

Other approaches would be possible (e.g. only use the SuperBASIC portion from the ROM, so that the rest of the OS is consistent, and use the older PM ROM instead of JS), but in any case the result will not be equivalent to the original: Components like most of the CON driver would be from a different ROM and there is no way to know for sure how it originally looked without recovering the missing ROM at $8000.

QL_screen_000.png

QL_screen_010.png

Looks great. Good to see something work out of it.

[QLvsJAGUAR]

Good work Daniele!

[QLvsJAGUAR]

Why not start a new thread "Original Sinclair QL (EP)ROM Software 13-2-84" under Software and another "Very early pre-mass-production QL" under Hardware?

[Chr$]

Why not start a new thread "Original Sinclair QL (EP)ROM Software 13-2-84" under Software and another "Very early pre-mass-production QL" under Hardware?

I will. Makes sense to have the search for the missing EPROM 3rd more easy for search engines to find.

[aalea]

I was checking the pictures of the PCB and comparing with other pictures and notice something that I think is important:

This board, ZX-83 Issue 2, is incompatible with ANY expansion board I know, And conecting any to it, can probably burn the QL, so Chr$, be aware.

The "problem" is that pin 32 A/B of this board is tied to the +5V Rail, while pin 32 B are tied to the Vinput Rail, in all the interfaces I know, this three pins are solder together, because all are Vinput.
so if you connect anything will put 12V in the MC68008, ZX8301, RAM, etc...

Probably the initial idea was to provide also 5V in the expansion port, (same as spectrum) and this is the reason of a 2nd 7805, but later, probably by economy or by heat disipation, remove the 5V from the port.

[Chr$]

I was checking the pictures of the PCB and comparing with other pictures and notice something that I think is important:

This board, ZX-83 Issue 2, is incompatible with ANY expansion board I know, And conecting any to it, can probably burn the QL, so Chr$, be aware.

The "problem" is that pin 32 A/B of this board is tied to the +5V Rail, while pin 32 B are tied to the Vinput Rail, in all the interfaces I know, this three pins are solder together, because all are Vinput.
so if you connect anything will put 12V in the MC68008, ZX8301, RAM, etc...

Probably the initial idea was to provide also 5V in the expansion port, (same as spectrum) and this is the reason of a 2nd 7805, but later, probably by economy or by heat disipation, remove the 5V from the port.

Good spot. You mean 31B is always tied to 32A and 32B? And those all supply 9v usually. My 31B connects to the input (not output) side of the main 7805, so yes, via any expansion card it would put that higher voltage through to the 5v rail!

I hadn't plugged anything in and I probably wouldn't have (but you never know, sometimes you just want to try something spontaneously). I'll make sure the expansion port is blocked with some tape or something.

The extra 7805 next to the serial port is actually a 7806 and appears to only feed power to the ZX8302, so I suppose it was discovered that that particular chip needed a bit more than the standard 5v. I'm just doing my webpage on the ZX-83 board, so will add the info about the expansion port.