[author : Richard Greenlaw] #Listing #Assembly #Algorithm #Programming

Extract : «  Many important programs, such as BASIC interpreters, assemblers, editors and some of the most sophisticated games, are sold without source code listings. Others were written directly in machine code. When you want to modify or repair them this program will help you find and understand the desired routines and can make a source file which can be edited and reassembled.

This disassembler is compact enough to fit in memory with your assembler/editor and the program to be modified, unlike disassemblers written in BASIC. It operates on a program in memory to produce disassembled source code or a hex and ASCII dump.

The disassembled source code can be displayed or printed or can be appended to a file in memory. Labels are formed from their values in the original program, thus carrying some useful information and requiring only two bytes each in the disassembler symbol table. They can, of course, take on other values when reassembled.

[...]

My system is a SOL-20 with 32K of RAM. My TTY does not have paper tape. I have a MICROPOLIS™ METAFLOPPY™ disk system but don’t have it doing assembly language yet. [...]  »

[author : Mike Gabrielson] #Microprocessor #Review

Extract : «  Intel has been slowly leaking information on its new 16 bit microprocessor, the 8086. Except for the concluding paragraph, the following is intended to be an objective report describing the various features of this new device. I have purposely skipped most of the hardware details (such as pinouts and interfacing), since that is not my area of expertise. Of course, all specifications are subject to change by Intel, and no endorsement of this article by them is implied.

Memory Organization

The 8086 can address one million bytes of memory, using a set of “segment” registers. [...]  »

[author : Les Hancock] #Listing #Assembly #Programming

Extract : «  This is a companion piece to the 1K Debugger, written to run on a Digital Group Z-80 system with ZE audio ROM, TVC-64 interface and TVC-64 monitor (see DDJ no. 24, p. 12). Starting the program causes it to clear the TV screen and print this menu:

TVC-64 UTILITIES

0 MONITOR

1 SEARCH

2 COMPARE

3 MOVE

4 HEX MODE [...]  »

[author : Richard B. Emerson] #Listing #Assembly #Printer #Interface

Extract : «  I am the proud owner of a PolyMorphic Systems Poly 88 with an 8080A CPU, Video Terminal Interface (VTI), 20K of memory from various vendors (Godbout, IMS, and IMSAI in order of preference), A Poly Cassette Interface, and a Poly Printer Interface. It is this last item that led me to write this article.

Sooner or later every computer owner wants a permanent copy of his triumphs (the very non-permanent CRT is fine for the less memorable events!) and at the same time it becomes painfully clear that a hard copy device is not cheap. Most printers that warrant any serious consideration are priced at or above the cost of a CPU and cabinet. I am fortunate enough to have access to a TI-745 portable terminal. This fact removed the first obstacle to getting a printer running. The second problem is the matter of finding the electronics to drive the printer. Unfortunately, most printers lack the good grace to allow you to hook your printer up to your particular bus, be it S-100, SWTPC, Benton Harbor, or Greyhound. This is where the manufacturers of parallel to serial and serial to parallel interfaces come in. They make boards that put the right signals in the right places so that your printer can be “heard”. My first thought was to buy a printer interface from PolyMorphic but a shortage caused by problems with the printed circuit manufacturer meant that the interfaces were as scarce as programs that run perfectly the first time. I decided to look elsewhere. [...]  »

[author : Carl Moser] #Listing #Assembly #Electronic #Storage #Interface

Extract : «  The February 1977 issue of Byte (page 82) contained an interesting article on a minimum hardware cassette interface. I have used this technique to develop a cassette I/O to record and load on tape at over 1600 baud. Because I don’t unpack bytes for recording, the effective data rate is over 160 bytes/second. The accompanying software listing for 6502 systems provides a record start sequence which requires at least ten 16 bytes followed with an OE byte to be inputted in sucession before loading can commence. At the end of loading, two byte checksum is used to detect errors. [...]  »

[author : John B. Trenholme] #Listing #Assembly #Programming #BASIC

Extract : «  This program renumbers Microsoft BASIC programs. It has been designed to have all its routines self-contained so that it doesn’t depend on the BASIC interpreter for subroutines. This makes it larger than it might be, but also means it will work with a variety of interpreters rather than just one. The specific version presented is for 3.1 8K cassette BASIC, but simple changes (below) will adapt it to other versions.

The program allows you to renumber starting from a line number in the middle of the program, rather than just from the beginning. This is so you can identify logical blocks of program statements by giving them line numbers starting with (for example) 1000, 2000, 3000, etc. Debugging is much easier when this is done, and other people can read the listing without getting hopelessly lost. [...]  »

[author : Larry A. Marek] #Listing #Assembly #Storage

Extract : «  Here are a set of routines I have worked out to take advantage of the tape routines in CUTER/SOLOS and the ALS-8 assembler. The ALS-8 assembler has the ability to assemble source code given to it by an outside driver in addition to the normal assembling from a file in memory. CUTER/SOLOS has the ability to appear like it is reading a byte from a tape whenever asked. “Appears” is important because the assembler could not perform its operations fast enough between bytes if the tape was actually in constant movement. By combining the two features, assemblies can be made of HUGE source files. The only restraint is that enough memory be available to hold the produced object code. [...]  »

[author : Larry Kheriaty and George Gerhold] #Languages #Programming

Extract : «  Increasing interest in using microcomputers as teaching tools in combination with increasing realization that BASIC is not a suitable language for most teaching applications has created a demand for microcomputer implementations of PILOT. This article is a status report on a number of microcomputer implementations of PILOT and a description of the extended version of PILOT which has been proposed as a national standard for the language. This extended version is called COMMON PILOT.  »