A Complete "microcomputer" with one SX28 chip!

Green Phantom

I have been working on a calculator-like hand-held microcomputer project at the beginning of this year with the SX Key Editor in SX/B.· A 10-key numeric, shifting and "command" button keypad encoder, a SERIN/SEROUT network combo, a small 96-byte RAM area; 8 bytes to display data to an 8-digit alpha/numeric serial LED dot-matrix display, 8 bytes for "device number" or "phone number", 16 bytes for text (as if you were displaying text on a 2x8 LCD display) and 64 bytes of "program memory."· I have found a collection of 8-digit, 5 x 7 dot matrix serial displays at Newark and Jameco.· Be sure to look up the first 4 alpha-numeric characters of the item manufacturer number: HCMS and the other 4 digits, 291X (X = 1 to 5, 6 or·9) or 297X.· Be on the lookout for HCMS-2919 and HCMS-2976 displays!· These generate a shiny blue color for each pixel but they are pricey!· X = 1 for yellow LEDs, 2 for "High-Efficiency" Red, 3 for green, 4 for orange and 5 for low-output red.· 6 and 9 are GaN Blue.· I have been in the process of editing the "program" language which I call "PhantAsm."· Values 0 to 255 are used, each with its own "mnemonic."· After I test the display and the SX program I have compiled up to now, this device could be programmed for use as a vintage "Stop, Thief!" board game "Crime Scanner" or a vintage LED "football" hand-held game!· I developed two different ASCII character display maps; one 64-character alphanumeric system and one 128-character 7-segment LED display emulation format.· The latters lights up the "decimal point dot" for values greater than 0 to 127.· Both are hexadecimal-ASCII-coded,·like the Nintendo Entertainment System console motherboard character ROMs.· Unlike the traditional ASCII character maps that designate the numbers 0 to 9 as character codes 48 to 57, numbers 0 to 9 here start at ASCII code value of 0.· This means that of the character codes 0 to 63 for the 64-character alphanumeric format or 0 to 127 for the 7-segment-emulated character set, numbers 0 to 9 start at 0 to 9, followed by the letters A to Z, so that the SX28-based source code can recognize the hexadecimal characters as 0 to 9 and A to F when displayed on the HCMS-series serial dot-matrix display.· You will need to download the data sheets for the HCMS-291X and HCMS-297X series devices at www.jameco.com and www.newark.com.· To prevent LED burnouts on the display, the devices have a special control RAM and ROM that sets the LED light intensity to 80% of its maximm capacity.· A resistor connected to the BLANK pin on the display package tied to GND allows you to manually, by hardware method, control the intensity of the LED display.· My SX/B program code even includes a small piece of code within the "program language" section of the source code to drive a piezo speaker for sound feedback!· The project is still in the works.·· I never tested it yet but so far I have been reading and reviewing the instructions in the HCMS-series display data sheets.

Green Phantom