Speculator

[arcadesy]

Great stuff Tony! Very exciting!

[Tony Brewer]

All my Einstein stuff was down from the attic before the cold spell in December. Most of the software effort will be directed to downloading Spectrum .SNA snapshot files via RS232 and it might be possible to go faster than 9600bps. Does the Einstein have a 8251 or 8251A? Any thoughts on other ways to get Spectrum progs into the Einstein apart from tape input?

[arcadesy]

Should be possible on a PC to copy spectrum prog files into .dsk image files and then load them on the Einstein using a Gotek.

[Tony Brewer]

Should be possible on a PC to copy spectrum prog files into .dsk image files and then load them on the Einstein using a Gotek.

What is the Gotek emulated diskette size?

My Einstein computer and colour monitor work, not tried the Speculator yet. Software for that could go in ROM and therefore would run on an Einstein with no working drives in theory. I've put the case screws back in but I think my USART chip is an NEC8251ACF, which is fine. RS232 speeds > 9600bps could be possible, perhaps signicantly faster, e.g. 57600.

[MikeDHalliday]

.dsk image HAS to be 211k in my experience. Anything more or less does not work with emulators and does not write back to floppy properly.

[arcadesy]

https://www.tatung-forum.co.uk/viewtopic.php?f=3&t=83 << interesting thread about getting 800k from a Gotek dsk image

[retrogamer]

I understand there are three Einstein floppy discs of Spectrum Programs that are already available to work with the Speculator.

Would they work from a Gotek image (in Drive 1 on my system)? I suppose what I'm asking is if the Speculator is happy to co-exist with whatever DOS is initialised.

I like the idea of using a Gotek for .SNA files, but appreciate each has to converted to a FlashFloppy readable DSK (or HFE or iMG). This is not ideal, but not impossible as Charlie Robson (aka sirmorris) has developed a tool for this (available on GitHub).

I also like the idea of including the traditional tape input facility, although I'm likely to use a digital player! But loading times are likely to be very much longer than one would like!

Serial transmission particularly with higher speeds is great, but a dedicated SD card storage system containing .SNA files as an add-on to the Speculator or even contained within the Speculator would probably be the most user friendly. This would avoid the need for a secondary unit for storage. I appreciate this would need to be implemented and more components would put the cost up, but I personally think this would be worth the extra money!

Richard

[Tony Brewer]

I sold all my Spectrum tapes bar one years ago, which means I can load only one game with the Speculator - and it works!

spectip1.jpg (193.24 KiB) Viewed 10498 times

spectip3.jpg (120.97 KiB) Viewed 10498 times

spectip4.jpg (159.78 KiB) Viewed 10498 times

A few of the Einstein's keys are sticky and CTRL doesn't work. Colours are washed out in the photos but monitor picture is amazingly vivid with minimum brightness and maximum contrast. You can see my original 1980s custom serial cable on the right and I'll test whether this can run at 57600 bps a bit later.

[Tony Brewer]

I understand there are three Einstein floppy discs of Spectrum Programs that are already available to work with the Speculator.

Would they work from a Gotek image (in Drive 1 on my system)? I suppose what I'm asking is if the Speculator is happy to co-exist with whatever DOS is initialised.

The existing Speculator software doesn't co-exist with anything really as it takes over all of RAM, but that could be changed I think.

[retrogamer]

It’s great that your Einstein is still operational, Tony. Thanks for the info. I’ve read Mike Smallman’s Speculator booklet again and am starting to understand its operation much more clearly.

I see that once you’ve loaded the spectrum game from tape you can save it to disc with a function key. And load this back again from disc with another function key. So actually the loading is nowhere near as problematic as I was anticipating. Appreciate there are some constraints (three 50k game dumps per disc, and the directory ideally has to be patched with another programme as I presume DOS is not used as the MOS routines are invoked directly). I’ve seen you can patch the SP1.com code to use other drives apart from Drive 0 so I could see that working with a Drive 1 Gotek in my case, so it’s all very exciting. I wonder if using ROM based code, although convenient, might make this a little more problematic.

So actually getting the Spectrum code into the machine is the issue. Although there are quite a few loaders already available! I can see why using snapshot files offers a much easier way to ensure many more games (probably all!) are compatible.

I suppose I’m thinking the original Speculator is the way to go for authenticity. But I wonder if the snapshot file could be lifted from disc directly using the current function key arrangement. If we generate a DSK image (or actual disc) with only one .SNA this would be fixed on specific tracks on the disc so would be easy to identify and load into memory. But I suppose the restriction is that you’d need a Gotek attached to the Einstein to either use or transfer the image to a real floppy. But many users do now use a Gotek.

Anyhow, it’s all very exciting and I’ve actually no problem with tape, serial or disc inputs. More than happy to go with whatever is easiest to implement in staying close to your original design!