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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 29th Jul 2023, 3:04 pm   #1
Phil__G
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Default ...and another Slothie MK14 joins the fray :)

https://youtu.be/SHPyy3m2kSo
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Old 29th Jul 2023, 3:11 pm   #2
SiriusHardware
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Default Re: ...and another Slothie MK14 joins the fray :)

Yours, we take it? Think yourself lucky not to have ever had a real one with its nearly unusable keypad!

Are you planning to write something on some other platform to load it up with (as you have Coolsnaz's fast loader / 'SCIOS 3' onboard). Or have you in fact already done that?
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Old 1st Aug 2023, 6:38 pm   #3
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Default Re: ...and another Slothie MK14 joins the fray :)

Great. Nice to see another Slothie Rev VI in action. I do like the large display. I've favored the bubble displays up till now but I think my eye's could benefit from something bigger.
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Old 1st Aug 2023, 8:54 pm   #4
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Default Re: ...and another Slothie MK14 joins the fray :)

Hi Ian, its a temporary display - from my old PC14 hand-wired birds-nest on stripboard
Somewhere I have one of Trevor H's proper display PCBs, but I'll also do a calculator-style display too, for show The pcb has a socket row so I can chop & change easily. The Realview arrived today thank you - it looks brilliant - and yesterday I posted your updated pic14 chip (latest version that preserves the pointers)
Hopefully you'll find its a good fix and we can call it a wrap - let me know please


Sirius I did have a real MK14 at one time, unfortunately sold it ages ago, before I got hooked on retro computing. It had horrible tagged-on pushbuttons that stood quite proud. Spoiled it but thats how it was when I bought it. Re the loader, Coolsnaz's input is so simple you can drive it from anything - might do a Z80 one for the RC2014, Ed's AY3-8910 soundcard has two uncommitted 8-bit /O ports. I'll do a little inline Intel-to-coolsnaz interface too, with the limitation that its one contiguous data block, ie the Intel addressing will be ignored. Over a short hard-wired link we can ignore checksums too so its really simple

Having an MK14 (see the 'an' there - I'm learning...) will certainly make PIC14 comparisons much easier, although I think with Realtime's bug-sleuthing that's sorted now

Cheers
Phil

Last edited by Phil__G; 1st Aug 2023 at 9:11 pm.
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Old 1st Aug 2023, 9:56 pm   #5
SiriusHardware
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Default Re: ...and another Slothie MK14 joins the fray :)

Actually you shouldn't throw away the ability to send multi-block Intel Hex because the CS2 protocol includes the address of the first databyte in each 'line' just like Intel Hex does.

With the MK14 having at least four separate 'islands' of RAM (even more if you have a RealView) it would be silly for your loader not to support uploading to multiple address areas from one Intel Hex file.

All you need to do is extract number of bytes, load address of first data byte, hex bytes from each Intel Hex Line and output those as a 'CS2' formatted line. The first data byte in each individual CS2 line is loaded at the address contained in the second and third byte of the CS2 line.

The only potential complication comes if you want to support the autorun address which is included at addresses FFFE-FFFF in a lot of the Intel Hex files lying around here.

If so, whatever is reading the hex file needs to collect and save the two bytes at addresses FFFE-FFFF if they are found in the Intel File and send the 'end' line as 00 ExecutionHibyte ExecutionLobyte. If no execution address found, send the 'end' line as 00 00 01 to jump to the monitor instead.
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Old 1st Aug 2023, 10:16 pm   #6
SiriusHardware
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Default Re: ...and another Slothie MK14 joins the fray :)

Quote:
It had horrible tagged-on pushbuttons that stood quite proud. Spoiled it but thats how it was when I bought it.
Ah, that explains it, you have the aura of one who has, at some point, attained MK14dom and yet strangely you don't - or didn't - have one.

I have seen some original MK14s, including one very recently, which have had decidedly un-stylish post-purchase keypads, but that was all the fault of SOC for making the supplied keypad so bad in the first place. It was so bad that one of the reviews of the MK14 even included the circuit diagram for an external keypad.
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Old 2nd Aug 2023, 11:11 am   #7
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Default Re: ...and another Slothie MK14 joins the fray :)

Ah I must be behind developments - the coolsnaz code snippet I have just loads raw bytes to an incrementing pointer, starting at whatever address was set in ram just like the original tape routine. I'll try to do some catch-up
And my roms have this addressing feature? Nice!
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Old 2nd Aug 2023, 11:21 am   #8
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Default Re: ...and another Slothie MK14 joins the fray :)

In the current version (which you have in your PROMs) you just start the loader code by entering its start address in the PROM and then start sending code to it, the loader then puts the code wherever it is told to put it.

Format of a 'Normal' line of CS2 format code is:

NN AH AL DB DB DB DB DB DB DB DB DB DB... .... ....

where DD are data bytes, NN is the number of data bytes in the line, AH and AL are the highbyte and lobyte of the address at which the first DB in the line should be loaded. There are no other start of line or 'end of line' characters so the last DB of one line is immediately followed by NN of the next.

For the 'end of file' line the format is

00 AH AL

(No data bytes, jump to the address in AH and AL).

AH and AL can be the execution address found in the Intel Hex file if there was one, but if not they must be 00 01 so that the loader exits to the monitor after loading.

Last edited by SiriusHardware; 2nd Aug 2023 at 11:50 am.
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Old 2nd Aug 2023, 11:56 am   #9
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Default Re: ...and another Slothie MK14 joins the fray :)

Caught by the edit-time-out-of-doom.

Quote:
"you just start the loader code by entering its start address in the PROM and then start sending code to it"
Would be more instructive if it said

Quote:
You just start the loader code by entering its PROM start address, and pressing Go. Then, start sending code to it.
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Old 2nd Aug 2023, 2:31 pm   #10
Phil__G
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Default Re: ...and another Slothie MK14 joins the fray :)

Yep got that thanks G, straightforward enough
I'm away from my workbench for a while so havent had any time on the Slothie v6 yet.
I manually typed in the code for the video above - and how I missed the PIC14 hexloader
I'll get some sort of loader sorted when I get back home
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Old 4th Aug 2023, 12:34 am   #11
SiriusHardware
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Default Re: ...and another Slothie MK14 joins the fray :)

Interesting thought...

As the PIC14 already has an integral serial hexloader, how about a little program for the PIC14 which sends whatever is loaded in the PIC14 out to the issue VI in CS2 protocol format? You only need two digital outputs + GND for the signalling. I think even the 876 version of the PIC14 has working Flag outputs? (or does it not? Maybe that is the difference between the 876 and 877 versions?)

To keep it simple you could just have the PIC14-side code 'clone' its entire RAM memory contents across to the same RAM memory blocks in the issue VI. Although that would seem wasteful, it transfers so fast that it wouldn't matter if some of what was being transferred was empty / unused memory.

Last edited by SiriusHardware; 4th Aug 2023 at 12:40 am.
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Old 4th Aug 2023, 9:33 am   #12
Phil__G
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Default Re: ...and another Slothie MK14 joins the fray :)

The 876 version of the PIC14 doesnt have the flags, sin, sout, sa,sb etc but I also have an 877 Philloupat one which does, so its possible - but the PIC14 only has 256 bytes of ram though so wouldnt transfer the larger programs unforch
I had thought about a PICL loader, that does have the flags etc...
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Old 5th Aug 2023, 2:34 pm   #13
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Default Re: ...and another Slothie MK14 joins the fray :)

Looks more authentic with a big electrolytic and a bubble display
Only for show though, I find it quite hard to work with the tiny display, my eyes are 45 years older than they were back in the day...
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Old 5th Aug 2023, 2:57 pm   #14
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Default Re: ...and another Slothie MK14 joins the fray :)

Looks great - I only use my bubble display for show otherwise it has the big one!
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Old 5th Aug 2023, 3:10 pm   #15
SiriusHardware
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Default Re: ...and another Slothie MK14 joins the fray :)

Phil, if you want an original type red reset switch for yours I may be able to oblige?
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Old 5th Aug 2023, 3:15 pm   #16
Phil__G
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Default Re: ...and another Slothie MK14 joins the fray :)

That would be nice!
Ta v much!
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Old 5th Aug 2023, 3:20 pm   #17
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Default Re: ...and another Slothie MK14 joins the fray :)

FYI, The full original size 'D6' series of push-switches are still available from RS etc: https://uk.rs-online.com/web/p/tactile-switches/1745136

(Red-actuator specified in the details - even though photo shows Black one):
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Old 5th Aug 2023, 11:13 pm   #18
Phil__G
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Default Re: ...and another Slothie MK14 joins the fray :)

Thanks Owen, I'll get some on my next order.
Had a rummage and found another Trev Hamblett display PCB so I can put the hand-wired ratsnest one back into the stash
Havent had time to try out the Realview module yet... should be fun!
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Old 6th Aug 2023, 1:37 pm   #19
SiriusHardware
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Default Re: ...and another Slothie MK14 joins the fray :)

So do I hold on to the one I have here?
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Old 6th Aug 2023, 2:17 pm   #20
Phil__G
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Default Re: ...and another Slothie MK14 joins the fray :)

They're only pennies, if I get a few I can give the rest away G, you keep it as a spare
But thanks anyway, another kind offer
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