K-2 Kradle?

[gammaray]

Ok. Where are the reverse engineering schematics and mechanical production drawings? And any ROM dumps?

[1024MAK]

A TS1000 / ZX81 will work with any DC power supply (with the correct polarity) that has an output of between 9V to 12V DC (smoothed, but unregulated), or if you have a regulated type, the acceptable voltage range is 7.5V to 13.2V DC. The power supply should of course have an output current rating of 700mA (computer with no more than one expansion) or higher.

With voltages of 10V and greater, the heatsink will run hotter than normal, but still safe for the computer.

Note that some RAM expansions based on 4116 DRAM chips need a DC power supply that has an actual measured voltage output of between 10.8V and 13.2V when connected to the computer regardless of what the label/rating plate says.

If you are not using a RAM expansion based on 4116 DRAM chips, and the computer will only be powered up for a short time, or you have a fan blowing air over the heatsink, you can increase the input voltage a bit higher. But I would not go above 15V.

Mark

[draketungsten]

God that's nice!!


@ draketungsten

I notice you're running what looks like an original treeforth EPROM.
Could I ask a small favour?

Could you compile and run the following and post a screen shot please?

ED OFF
CO REV

: z 1000 0 do i . loop ;

I've never come across an original Forth EPROM before, having to make do with emulator copies, and this might just satisfy a curiosity I have re re screen layout.


Regards.

Moggy.

Here you go!

Also, is it normal for "MEM ." to print a negative? Looks like the Tree-Forth board is upping the ram to 16k...?

[1024MAK]

Moggy will love you for those pictures

Thanks

Mark

[draketungsten]

Gladly!

Unfortunately the stock ROM doesn't seem to boot with the Kradle connected, but it does boot by itself. I just get a white screen. I'll do some digging around to see what that means but I was hoping the problem was not enough power but I have it hooked up to 9V 1.2A. I also tried 12V with no change.

I've read that the more RAM, the longer these can take to show the prompt... About how long does 64K take to check? Tree-Forth loads almost instantly but I suspect the daughter board is overriding the Kradle's RAM with its own 16K... If that's the case, I suspect since the Kradle seems to function correctly in Tree-Forth it's a RAM issue on the Kradle board.

Not sure if any of the extras (serial, joystick, tape loader improvements) on the Kradle work with Forth. Is there a suggested reading list for getting started with Forth? I found a PDF for ZX-Forth but I'm not sure if that translates well to a Tree-Forth ROM...

Thanks!

[mrtinb]

I found a PDF for ZX-Forth but I'm not sure if that translates well to a Tree-Forth ROM...

Tree-forth manual is posted here: viewtopic.php?f=11&t=459#p4087

[Moggy]

Thanks for those pictures draketungsten, question answered.

With the copied emulator ROM there was always a display problem insofar as the display was too far to the right and the inverse "mask" didn't stretch across the full width of the display leaving half a chr un-inverted, yet works perfectly in the emulator Eighty One. I always wondered if the emulator ROM was altered to display the inverse perfectly and centred in Eighty One but when run on a real 81 caused the display to be as shown and until now have never had a real ROM to test against but thanks to you that one has been put to bed.

Many thanks again for taking the time to provide screen shots very greatful.

As to the MEM thing as far as I can recall H4th/Treeforth was never meant to run over 16k so perhaps the 64k you have is klutzing up the MEM report which is also reported incorrectly on the latest version of Eighty One as 31344 (on my copy at least) and correctly as 14976 on my 16k bog standard system.

[draketungsten]

I found a PDF for ZX-Forth but I'm not sure if that translates well to a Tree-Forth ROM...

Tree-forth manual is posted here: viewtopic.php?f=11&t=459#p4087

Ah thanks for that!

[draketungsten]

Thanks for those pictures draketungsten, question answered.

With the copied emulator ROM there was always a display problem insofar as the display was too far to the right and the inverse "mask" didn't stretch across the full width of the display leaving half a chr un-inverted, yet works perfectly in the emulator Eighty One. I always wondered if the emulator ROM was altered to display the inverse perfectly and centred in Eighty One but when run on a real 81 caused the display to be as shown and until now have never had a real ROM to test against but thanks to you that one has been put to bed.

Many thanks again for taking the time to provide screen shots very greatful.

As to the MEM thing as far as I can recall H4th/Treeforth was never meant to run over 16k so perhaps the 64k you have is klutzing up the MEM report which is also reported incorrectly on the latest version of Eighty One as 31344 (on my copy at least) and correctly as 14976 on my 16k bog standard system.

Interesting. In that case, I may need to pick up one of those new replacement membrane keyboards to troubleshoot my base machine...

[Moggy]

@ draketungsten.

Just noticed the part of your post re Forth primers etc.

The short answer is, nothing you find on the web(and there's tons of it) be it Leo Brodie's stuff or who ever will translate in any meaningful way into Treeforth sadly.

There are that many bloody dialects of the language that it becomes frustrating.
You can get two thirds of the way into something good when suddenly a Forth primitive like RECURSE will rear its ugly head and guess what ? Treeforth has no such word in its lexicon so right lets try a few more examples TUCK, ROLL these are common tenants of other Forths but sadly not this one so my advice is to find your Forth of choice learn it well and stick with it.

Tree/H4th is quite a nice dialect to play with quite honestly and one I love to death it can multitask with devices in the out side world should you have the skills to create such things
it deals well with 32 bit maths and has a few rudimentary 64 bit maths operators as well and the ability to create screens of varying sizes around the display area and frankly it's just a nice dialect to have fun with.

If however you see it as a way to shortcut learning assembler for games creation, which is all most want to do with Sinclair machines in my opinion at least then disappointment lies ahead as from a graphics perspective it's a dead loss.

I will dig something out however and attach.

Here we are...

http://www.wulfden.org/downloads/Forth_ ... gForth.pdf