Tiny SC/MP system !!!

[Mark1960]

I haven’t tried it yet, but nice to know its there.

I’m looking at options for trapping illegal instructions. Equivalent function to the PE article should be only two halves of a ‘74 and either dual 4 input Nor or ‘138.

Then I got thinking about using a prom, or modern flash, to translate every instruction fetch with a lookup table, with a ‘245 to bypass the prom for all other data. Then the illegal instructions are all translated to XPPC P3 and the sense input is not used. The OS could read the instruction that caused the trap without translation. It wouldn’t take much more to extend this to provide a non maskable interupt

[Realtime]

Originally Posted by Phil__G

I would love to know if anyone has tried it. As far as I'm aware its just me & Benny (Audiokit)
Files & updated docs are in the KitbugPlus.zip file on my scamp page.
Cheers
Phil

I'll definitely be trying it in due course when I get around to building the micro-introkit. But I'm also thinking of hosting it on the LCDS as that should easily accommodate it and maybe even talk to the TELEKIT (eventually).

[Phil__G]

If you've at least 1.5k of ROM space and some wrap-around RAM visible below that, it should be just a case of
setting the baud rate back to 110 Ian

[Realtime]

Whilst I ponder my next move with TELEKIT I thought I'd try and get KitbugPlus running on the LCDS.

The NSC processor module has a SC/MP I (1MHz). The module at the front is a RAM/ROM board I made for something else, re-wired for the LCDS pinout. Currently 2K ROM and 2K RAM but can be up to 32K of each.
It took me a while to remember that the LCDS is using SENSEB for TELEKIT and causing a conflict but once that was sorted KitbugPlus sprang into LIFE

I'm using the 2400 baud version, but with Teraterm set to 1200 baud, as the 1MHz SCMP runs half the speed of the 4MHz SCMP II.


Nice work Phil

[Phil__G]

Thats brilliant, oh I'm so chuffed, thank you Ian we are three!

Any chance of zipping a few hi-res pics of the LCDS? Will you be taking it to Cambridge?

[Phil__G]

Another throw-away demo:
https://youtu.be/V5eY8fGy9R4

[Realtime]

Originally Posted by Phil__G

Any chance of zipping a few hi-res pics of the LCDS? Will you be taking it to Cambridge?

I will take some nice photos of it and post them on the LCDS thread. I'm going to take it to CfCH in the hope that someone will very generously give me a corner of their table to perch it on . I'll be there on the Sunday.

[Timbucus]

Originally Posted by Realtime

I will take some nice photos of it and post them on the LCDS thread. I'm going to take it to CfCH in the hope that someone will very generously give me a corner of their table to perch it on . I'll be there on the Sunday.

I am sure there will be space - I was planning on not taking so much so probably will be on our table - looking forward to seeing it.

[Realtime]

Thanks Tim, appreciate that. Looking forward to meeting people on the Sunday.

[Realtime]

Here's a new program to run on Kitbugplus - the KitBug+ Digital Clock. Just a bit of fun, but it gave me a genuine reason to use the single step and halt debug features on the LCDS - not bad once you get the hang of the keypad layout.

• Timings are for a 4MHz SC/MP and 2400 baud rate
• The terminal window needs to be at least 64 characters wide, with scrolling enabled (default for Teraterm)
• Load at $800 (S800)
• Set the clock's Hour and Minutes at addresses $F00 and $F01 respectively (MF00). If they are not in range then they are automatically set to 00. Seconds are always initialised to 00
• Run from $860 (G860)
• Due to the time taken to output the serial data, the displayed time increments in 2 second intervals. Constants DELAY_DISP and DELAY_ACC in the .ASM may be tweaked to fine tune the timing

I'll post a short video in the near future for the few that aren't running Kitbug+ .

Enjoy!

[Phil__G]

Very clever
I had to look up .HS as I've not used that one before
https://youtu.be/gDAeOglaFwE

[Realtime]

A v2 already . What escape characters have you used to make the cursor return to the top left after each display cycle?

[circuitryboy]

Originally Posted by Mark1960

I was wondering if all the gaps in the instruction table were treated as NOP by the INS8060. Also what happens for the two byte NOPs, does the second byte still get fetched and is it ignored. Has anyone tried these undefined instruction codes?

The SC/MP Technical Description has this in Instruction Summary (below)
Presumably if an invalid instruction byte has Most Significant Bit set then it's a 'two-byte NOP' and the second byte will be ignored.
But I've never investigated further.
The maximum of 10 microcycles suggests a second Read Cycle is being taken.
It seems that x08 is actually an invalid instruction that is known to 'use' 5 microcycles!

[Mark1960]

Originally Posted by circuitryboy

The SC/MP Technical Description has this in Instruction Summary (below)
Presumably if an invalid instruction byte has Most Significant Bit set then it's a 'two-byte NOP' and the second byte will be ignored.
But I've never investigated further.
The maximum of 10 microcycles suggests a second Read Cycle is being taken.
It seems that x08 is actually an invalid instruction that is known to 'use' 5 microcycles!

Thanks, I never thought to read the detailed description of the NOP instruction. There is probably not an easy way to make use of the second byte of the two byte NOPs, though I guess that could be used to pass a byte to software interupt routine, but then the interupt routine has to figure out if it was a double byte illegal instruction or if the second byte was a single byte illegal instruction. It might be easier to translate all illegal instructions to XPPC P3 through the prom/eeprom.

[Phil__G]

I was looking through some Elektor SC/MP stuff and found the Elektor ESS-02 tunes, Silent Night, Oh Tannenbaum, Jingle Bells etc
These binaries load directly into KitbugPlus on the 'micro introkit' board without any re-assembly or modification, and play perfectly (though a bit fast)!
Just use SC00 and 'File, Send file' on Teraterm with 'binary' ticked, when the FTDI led stops flashing press reset, then type GC00
Audio appears on the flags as you'd expect
Just in time for Christmas!

[Phil__G]

Originally Posted by Realtime

A v2 already . What escape characters have you used to make the cursor return to the top left after each display cycle?

Sorry Ian only just spotted your post
Here ya go:

    ;Main routine for displaying Clock on terminal
DISP_CLK: 
	LDI	/PUTC-1
	XPAH	P3		; P3 --> PUTC-1
	LDI	#PUTC-1
	XPAL	P3

	LDI	$1B
	XPPC	3
	LDI	'['
	XPPC	3
	LDI	'H'
	XPPC	3
   	
    LDI $06       ; 6 lines per display to output
    ST COUNT(P2)
    LDI $00       ; points to row in character table
    ST ROW_OFF(P2)
AGAIN:

or shorter:

DISP_CLK: 
	LDI	/IPRINT-1
	XPAH	P3
	LDI	#IPRINT-1
	XPAL	P3
	XPPC	P3
	.DB	$1B,"[H",0

    LDI $06       ; 6 lines per display to output
    ST COUNT(P2)
    LDI $00       ; points to row in character table
    ST ROW_OFF(P2)
AGAIN:

[Phil__G]

(Forgot to mention this, but the edit timeout got me again...)

I've got into the habit of clearing memory before starting anything, using Copy Down on ascending addresses:

[Realtime]

Originally Posted by Phil__G

Sorry Ian only just spotted your post
Here ya go:

    ;Main routine for displaying Clock on terminal
DISP_CLK: 
	LDI	/PUTC-1
	XPAH	P3		; P3 --> PUTC-1
	LDI	#PUTC-1
	XPAL	P3

	LDI	$1B
	XPPC	3
	LDI	'['
	XPPC	3
	LDI	'H'
	XPPC	3

Thanks Phil that works great (of course )

[Phil__G]

Weird, this morning I noticed that the S command description was missing from the KB+ document, did I accidentally remove it or did I forget to add it in the first place, I dunno
Anyroadup, the KitbugPlus.zip file now has an up-to-date PDF. No code changes.
Cheese
Pies

[Phil__G]

Sorry, spoke too soon, today I noticed that although the Copy command was working fine copying up or down on disparate or overlapping areas, it was actually copying one too many bytes.

Apologies but consequently there is a code update today after all
KitbugPlus.zip

Ta
Phil