Sinclair ZX80 / ZX81 / Z88 Forums

Posted: **Sat Dec 05, 2020 3:20 am**

"Your Computer" March 83

Posted: **Sat Dec 05, 2020 8:02 am**

The XZ81 sounds like an interesting machine. Does anyone have one of these extra r@re machines?

Mark

Posted: **Sat Dec 05, 2020 9:11 am**

HI,

The XZ-81 is a Timex-Sinclair computer like… with 1K RAM and a destroyed keyboard !

https://www.youtube.com/watch?v=KmdAQl2lSgA

Posted: **Sat Dec 05, 2020 9:19 am**

In case of RAND USR *** , the BC return value is store in 16434/16435...

We can retrieve this value using a RAND USR ***ROM*** to get this value ? as BC value in a LET command…
LD BC,(16434) ; $4030
RET

Posted: **Sat Dec 05, 2020 10:38 am**

Code: Select all

1 REM xxxxxxx
2 FOR A=0 TO 5
3 POKE 16514+A,PEEK (3379+A)
4 NEXT A
5 POKE 16514,33
6 POKE 16515,61
7 POKE 16520,201
8 RAND 12345
9 POKE 16445,PEEK 16434
10 POKE 16446,PEEK 16435
11 PRINT USR 16514

Code: Select all

;------- TASM ASM mnemonics. -------
; Compile this file using:
; Set TASMOPTS = -b
; tasm -80 ThisCode.tas MyBinary.BIN
;-----------------------------------
; Zx81 Program name: VB81 XuR [RAND.bas] :
; REM   line   name: 1 REM:     7 Bytes@4082-4088

#define ORG  .org       ; TASM cross-assembler definitions
#define equ  .equ
;-----------------------------------

;------------------------------------
;-Basic sub-routine entry.          -
;+----------------------------------+
; Lb4082  ;  <- USR Basic Enty.
;+----------------------------------+

ORG $4082 ; [@16514/@h4082]
Lb4082: ; <- USR Basic Enty.
	LD HL,$403D 
	LD C,(HL) 
	INC HL 
	LD B,(HL) 
	RET ; ==========================
.end

We had to move the 16434/45…
this address is used in LET/USR function.

RAND.P: (1.15 KiB) Downloaded 152 times

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