peraino@gmu90x.gmu.edu (peraino) (11/29/89)
Subject: SYS, MAKE, ->PROG, PROG->, UNPIXEL programs for the HP28S | | | Forwarded for Eric Toonen, who doesn't have USENET access. | | | The SYSEVAL command does exactly what its name suggests: It EVALuates a SYStem object. Instead of writing programs like << #A SYSEVAL #A SYSEVAL >> You should be able to write << System Object System Object >> To do the same job. Here are a small set of utilities and an example to generate those System Objects. These will work on VERSION 2BB ONLY! If you are not very interested in using SYSEVALS (and therefore SYS) a lot, DO NOT type them in, because they can be extremely dangerous! Please type them in exactly as they are written, because a typo can cause a Memory Lost !! First, save anything on stack you want to keep, and type ---------------------------------------- | CLEAR HEX 64 STWS | First, set correct modes | << #71BD SYSEVAL | Make a temporary SYSEVAL-version #3E9D7 SYSEVAL | of SYS. >> | 'SYS' STO | chk[A4C8] | << #200E SYSEVAL | Make a temporary SYSEVAL-version #3EEB SYSEVAL | of MAKE. >> | 'MAKE' STO | chk[1525] | ** BEWARE THAT THE STACK IS EMPTY | AT THIS POINT ! | #71BD SYS | Use SYS to generate two System #3E9D7 SYS | Objects on the stack MAKE | Use MAKE to generate them into 'SYS' STO | a program, and we have the new SYS! | | ** STACK MUST BE EMPTY NOW! | #200E SYS | Again, use SYS to get the System #3EEB SYS | Objects MAKE | And collect them into a program 'MAKE' STO | Called MAKE. | Stack must be empty #C53B SYS | Generate ->PROG program #3EEB SYS | MAKE | '->PROG' STO | | Stack must be empty #78A6 SYS | Generate PROG-> program 'PROG->' STO | Because there is only one object, | there is no need to MAKE ---------------------------------------- Sorry, posting the checksums of the system-object programs is nonsense, the checksum program doesn't see differences between System Objects. (Bob?) Now, you will have four DANGEROUS programs. These can be very handy, but can do enormous damage if you use them wrong. What they do: First, let me explain: Internally, lists and programs are stored in almost the same way (a list-structure). With these programs, you can do with programs what LIST-> and ->LIST do with lists, and thus can put any sequence of objects in a program. Why, you might ask, do I need this? Well, System Objects cannot be typed in. Actually, System Object appears on the screen, as soon as the display routines don't know how to display it in another way, therefore, in-line machine code, and actual system-objects are displayed as "System Object". To make quick-n-dirty programs (that is, use Syseval addresses that don't check arguments, instead of the user-functions), you just generate their objects by using SYS, and collect them into a program with MAKE or ->PROG. Because you cannot edit those programs, they can be put on stack with PROG->. PLEASE NOTE: Sys, ->Prog and Prog-> DO NOT CHECK STACK-DEPTH and ARGUMENT TYPES. Usage: SYS (Generate system-objects) !!! Needs a binary integer in level 1. !!! Returns a System-Object in level 1. Example: #A SYS Returns a System Object, which can be EVAL'd. Try this! MAKE (Generate program from stack) Takes total stack, and puts it into a program. If the stack is empty, the program will be empty. If there are no << and >> on stack, the program will not have them either. Example1: CLEAR MAKE 5 SWAP Generates an empty program, which is invisible for the user. Example2: CLEAR 2 5 { + } 1 GET MAKE Generates the program 2 5 + (without << and >>) ->PROG (to program) !! Takes a real <n> from level1, and stack depth should be <n>+1 !! Returns a program with <n> objects. Example: 2 5 { + } 1 GET 3 ->PROG Generates the same program as in Example2 of MAKE. PROG-> (program out) !! Takes a program in level1 !! Returns all objects separate to stack, and then the number of objects. Example1: << 2 5 + >> PROG-> Example2: << 2 5 + >> PROG-> ->PROG Example using SYS and MAKE, generating an UNPIXEL function, which is exactly compatible with PIXEL. 'UNPIXEL' Type in the following, and check the checksum! ---------------------------------------------------------------- << CLEAR { C->R } 1 GET #2484B SYS #3D5F6 SYS #020E5 SYS #24927 SYS #3D7F8 SYS #11D1D SYS 31 #020E5 SYS #11D82 SYS #020E5 SYS #3D815 SYS #11D1D SYS 136 #020E5 SYS #11D82 SYS #3D6B8 SYS #3D682 SYS #11D1D SYS #11D48 SYS #3D72C SYS #3D636 SYS #11D1D SYS #11D48 SYS 31 #020E5 SYS #11D1D SYS #0206E SYS #11B17 SYS #020E5 SYS #11B17 SYS #06CB9 SYS #3D636 SYS #0C1DD SYS #0206E SYS #072E9 SYS #06E55 SYS #020E5 SYS #3ECC2 SYS #06E55 SYS #06CB9 SYS #3D65C SYS #06CB9 SYS #18A85 SYS #3DC5F SYS #1ADF2 SYS #0211A SYS MAKE 'UNPIXEL' STO >> 'MUNPIXEL' STO ---------------------------------------------------------------- The checksum of MUNPIXEL is [8237] (I have tried it again from this text, and am sure there are no typo's) ----------------------------------------------------------------------------- Eric Toonen Snailmail: Djept-Zuid 6 | Hogeschool-Eindhoven: s89406143@hsepm3.hse.nl 5502 RP Veldhoven | (Not an uucp-address) The Netherlands | (Might work on SURFNET (?)) -----------------------------------------------------------------------------
e85_nisse@tekno.chalmers.se (NILS ANDERSSON) (11/29/89)
I have seen this heading for an article posted here in comp.sys.handhelds: -> 709 HP28s program to turn a pixel off (opposite of PI 168 29-Nov-89 But when I try to read it I get this article instead: === Group: comp.sys.handhelds, Item 709 (Current Item Range #678 - #709) Subject: Re: *un*happy endings (*** SPOILERS ***) From: isbell@pyr.gatech.EDU ( Charles L. Isbell), Georgia Institute of Technolog Date: 29 Nov 89 00:28:09 GMT Ignoring "horror" films, howzabout: ! (deleted stuff) === I have located this article in rec.arts.movies. Could someone please mail me the article about pixels on the HP-28S? (I guess this computer doesn't behave correct...) Thanks in advance!!! Nils Andersson email: e85_nisse@tekno.chalmers.se