The Sinclair QL Forum

ql_freak wrote:I also have renamed the function, cause it is no BASIC VAL() function. Look what VAL in Visual BASIC, C64 BASIC, ... does. The Spectrum VAL() function is special. So I choosed the name EVAL(expr$,error_result$). This is the same function name as in Python (which also has such a nice function). BTW: A normal BASIC compatible VAL() function (not Spectrum VAL) would be useful too.

janbredenbeek wrote:It was originally released on EPROM with a cassette interface, but still allows loading programs from ASCII files so you don't need cassettes now :D

ql_freak wrote:

stevepoole wrote:Hi,
EmmBee's program works well on my SGC QL, but not under SMSQ, nor therefore with QPC2, as stated.

It worked here on my QPC2, but the problem is, that it doesn't return an error, if there is an "error in expression". In addition it does not work with MultiBASIC jobs.

So I have improved the program. It is now compatible with MultiBASIC and it needs a second string parameter, which must be a string variable, as it is assigned an error message, so that you can test afterwards if there was an error. If there was no error (a correct expression was passed in the first parameter) this variable is set to the empty string ("").

I also have renamed the function, cause it is no BASIC VAL() function. Look what VAL in Visual BASIC, C64 BASIC, ... does. The Spectrum VAL() function is special. So I choosed the name EVAL(expr$,error_result$). This is the same function name as in Python (which also has such a nice function). BTW: A normal BASIC compatible VAL() function (not Spectrum VAL) would be useful too.

Here is the code together with a simple test program, Turbo Toolkit Version 3.40 or higher(!) and SuperToolkit II is required (edited 2017 Mar 23: added po% and pi% to LOCAL statement in 32130):

Code: Select all

100 REMark Test for EVAL(string$,error_result$) SuperBASIC function
110 :
120 a$="10":rorre$="":REMark default no error
130 a=EVAL("3*4+a$",rorre$)
140 IF (rorre$ <> "")
150   PRINT rorre$
160 ELSE
170   PRINT a
180 END IF
30000 :
32100 REMark Support PROCedures AND FuNctions
32110 :
32120 DEFine FuNction EVAL(x$,err$)
32130   LOCal result,test$,po%,pi%
32140   err$="":pi%=FOPEN("CON")
32150   po%=FOPEN("CON"):CLOSE#po%:CLOSE#pi%
32160   IF FOP_NEW(#po%,"PIPE_1024"):err$="Cannot open PIPE":RETurn 0
32170   CONNECT po% TO pi%
32180   result = 0
32190   test$="PRINT#po%,"&x$
32210   IF x$ <> FILL$(" ",LEN(x$))
32220     COMMAND_LINE JOBID()
32260     TYPE_IN test$&CHR$(10)
32270     TYPE_IN FILL$(CHR$(194),LEN(test$))&"CONTINUE"&CHR$(10):STOP
32280     CLOSE#po%:IF EOF(#pi%):CLOSE#pi%:err$="Error in expression":RETurn 0
32290     CLOSE#pi%
32300     TYPE_IN "result = " & x$ & CHR$(10)
32340     TYPE_IN "CONTINUE" & CHR$(10)
32380     STOP
32420   END IF
32460   RETurn result
32500 END DEFine EVAL

ql_freak wrote: Wow, there was a cassette interface for the QL, I have never heard from one. What formats can it read? Is there SuperTape (from the German c't magazine) available? It was available for most computers (Spectrum, C64, Dragon, ...), much faster than the inbuilt cassette software and was therefore often used to transfer programs from one system to another. I have some cassettes with BASIC programs from my first "computer", a Sharp Pocket PC-1500. And as far as I can remember, I have a SuperTape implementation for it.

Do you have any circuit diagramms for the cassette interface?