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Groups > comp.sys.apple2.programmer > #3842
| From | "James Davis" <JPD.Enterprises@Live.com> |
|---|---|
| Newsgroups | comp.sys.apple2.programmer |
| Subject | Re: Origin of TEMPOP $2E ? |
| Date | 2017-08-26 16:38 -0700 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <ont0pd$1o0h$1@gioia.aioe.org> (permalink) |
| References | <a259f773-36e0-4705-bcf4-ad4d19d4ce1f@googlegroups.com> |
Hi MP,
This routine in the Apple IIe Technical Reference Manual (pgs.
334-335) firmware listing starts-ends at $F882-$F8B6. It looks
like it checks the validity of opcodes.
James Davis
"Michael Pohoreski" wrote in message
news:a259f773-36e0-4705-bcf4-ad4d19d4ce1f@googlegroups.com...
AppleWin includes this symbol:
002E MASK/TEMPOP
Obviously the first part, MASK, is the GR pixel mask used for
plotting ...
36 MASK EQU $2E
F800: 4A 102 PLOT LSR ;Y-COORD/2
F801: 08 103 PHP ;SAVE LSB IN CARRY
F802: 20 47 F8 104 JSR GBASCALC ;CALC BASE ADR IN
GBASL,H
F805: 28 105 PLP ;RESTORE LSB FROM
CARRY
F806: A9 0F 106 LDA #$0F ;MASK $0F IF EVEN
F808: 90 02 107 BCC RTMASK
F80A: 69 E0 108 ADC #$E0 ;MASK $F0 IF ODD
F80C: 85 2E 109 RTMASK STA MASK
F80E: B1 26 110 PLOT1 LDA (GBASL),Y ;DATA
F810: 45 30 111 EOR COLOR ; EOR COLOR
F812: 25 2E 112 AND MASK ; AND MASK
F814: 51 26 113 EOR (GBASL),Y ; EOR DATA
F816: 91 26 114 STA (GBASL),Y ; TO DATA
F818: 60 115 RTS
... but does anyone know where the symbol TEMPOP comes from? A
little google-fu reveals nothing. :-/
As far as I can tell it looks like someone was trying to describe
FORMAT from Apple //c Reference Manual Vol 2
42 FORMAT EQU $2E ;temp for opcode decode
43 LENGTH EQU $2F ;temp for opcode decode
F8A9: AA 200 GETFMT TAX
F8AA: BD A6 F9 201 LDA FMT2,X ;INDEX INTO PRINT
FORMAT TABLE
F8AD: 85 2E 202 STA FORMAT ;SAVE FOR ADR
FIELD FORMATTING
Doesn't look like it is worth keeping ... unless someone can shed
some more light on this one.
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Origin of TEMPOP $2E ? Michael Pohoreski <michael.pohoreski@gmail.com> - 2017-08-26 09:23 -0700
Re: Origin of TEMPOP $2E ? "James Davis" <JPD.Enterprises@Live.com> - 2017-08-26 16:38 -0700
Re: Origin of TEMPOP $2E ? Michael Pohoreski <michael.pohoreski@gmail.com> - 2017-08-28 07:15 -0700
Re: Origin of TEMPOP $2E ? gids.rs@sasktel.net - 2017-08-28 14:30 -0700
Re: Origin of TEMPOP $2E ? Michael Pohoreski <michael.pohoreski@gmail.com> - 2017-08-28 21:24 -0700
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