Editing GEM (desktop environment) (section)

==={{anchor|GDOS|GIOS|GSX 1.0|GSX 1.1|GSX 1.2|GSX 1.3}}GSX===
[[File:Cbasic.svg|thumb|GSX and CBASIC workflow diagram]]
[[File:CP⁄M Ad, InfoWorld, November 29, 1982.jpg|thumb|GSX advertisement in 1982]]
In late 1984, GEM started life at DRI as an outgrowth of a more general-purpose graphics library known as GSX (Graphics System Extension),<ref name="Wong_1984_GSX"/> written by a team led by Don Heiskell since about 1982.<ref name="DRI_1984_DD"/> Lee Jay Lorenzen (at Graphic Software Systems) who had recently left [[Xerox PARC]] (the birthplace of the modern GUI) wrote much of the code. GSX was essentially a DRI-specific implementation of the [[Graphical Kernel System|GKS]] graphics standard proposed in the late 1970s. GSX was intended to allow DRI to write graphics programs (charting, etc.) for any of the [[8-bit]] and [[16-bit]] platforms [[CP/M-80]], [[Concurrent CP/M]], [[CP/M-86]] and [[MS-DOS]] ([[NEC APC-III]]) would run on,<ref name="DRI_1984_MicroNotes3"/> a task that otherwise would have required considerable effort to port due to the large differences in graphics hardware (and concepts) between the various systems of that era.<ref name="Wong_1984_GSX"/>

GSX consisted of two parts: a selection of routines for common drawing operations, and the device drivers that are responsible for handling the actual output. The former was known as '''GDOS''' (Graphics Device Operating System) and the latter as '''GIOS''' (Graphics Input/Output System),<ref name="Elliott_GSX"/> a play on the division of CP/M into the machine-independent [[BDOS]] (Basic Disk Operating System) and the machine-specific [[BIOS]] (Basic Input/Output System).<ref name="Wong_1984_GSX"/> GDOS was a selection of routines that handled the GKS drawing, while GIOS actually used the underlying hardware to produce the output.<ref name="Wong_1984_GSX"/>

==== Known 8-bit device drivers ====
* DDMODE0 [[Amstrad CPC]] screen in mode 0
* DDMODE1 Amstrad CPC screen in mode 1
* DDMODE2 Amstrad CPC screen in mode 2
* DDSCREEN [[Amstrad PCW]] screen
* DDBBC0 [[BBC Micro]] screen in mode 0
* DDBBC1 BBC Micro screen in mode 1
* DDGDC, DDNCRDMV [[NEC μPD7220]]
* DDVRET  [[VT100]] + Retro-Graphics GEN.II (aka 4027/[[Tektronix 4010|4010]])
* DDTS803 [[TeleVideo]] screen
* DDHP26XX HP 2648 and 2627 terminals<ref name="DDHP26XX_2020" />
* DDQX10  [[QX-10]] screen
* DDFXLR8 Epson [[lo-res]], 8-bit
* DDFXHR8 Epson [[hi-res]], 8-bit
* DDFXLR7 [[Epson]] and Epson-compatible printers
* DDCITOLR [[C. Itoh]] 8510A [[lo-res]]
* DDCITOH C. Itoh 8510A
* DD-DMP1 Amstrad DMP1 printer (aka [[Seikosha]] GP500M-2)
* DDSHINWA Printers using Shinwa Industries mechanism
* DDHP7470, DD7470 [[Hewlett-Packard]] [[HP 7470]] and compatible pen plotters, [[HP-GL/2]]
* DD7220 Hewlett-Packard HP 7220, [[HP-GL]]
* DDGEN2  [[ReGIS|Retro-Graphics]] GEN.II ([[Ratfor]] source code in ''Programmer's Guide'')
* DDHI3M   [[Houston Instrument]] HiPlot DMP
* DDHI7M Houston Instrument HiPlot DMP
* DDMX80 [[Epson MX-80]] + [[Graftrax Plus]]
* DDESP Electric Studio Light Pen ([[Amstrad PCW]])
* DDOKI84 [[Oki Data]] Microline
* DDMF GEM metafile
* DDPS [[PostScript]] metafile

==== Known 16-bit device drivers ====
* DDLA100 [[Digital Equipment Corporation|DEC]]
* DDLA50 DEC
* DDNECAPC [[NEC APC]]
* NCRPC4 [[NCR Corporation|NCR]] DecisionMate V
* IBMBLMP2, IBMBLMP3 [[IBM]] [[Color Graphics Adapter|CGA]] monochrome mode
* IBMBLCP2, IBMBLCP3 IBM CGA color mode
* IBMCHMP6
* IBMEHFP6, IBMEHMP6, IBMELFP6 IBM [[Enhanced Graphics Adapter]]
* HERMONP2, IBMHERP3, HERMONP6, [[Hercules Graphics Card]] (720×348)
* UM85C408AF UMC [[Video Graphics Array|VGA]] Graphics<ref name="UMC" />
* DDIDSM IDS Monochrome
* DDANADXM Anadex DP-9501 and DP-9001A
* DDCITOLR [[C. Itoh]] 8510A [[lo-res]]
* DDCNTXM [[Centronics]] 351, 352 and 353
* DDDS180 Datasouth
* DDOKI84 [[Oki Data]] Microline
* DDPMVP   [[Printronix]] MVP
* DD3EPSNL IBM/Epson FX-80 lo-res Printer (see DDFXLR7 and DDFXLR8)
* DD3EPSNH IBM/Epson FX-80 hi-res Printer (see DDFXHR8)
* DD75XHM1 [[Regnecentralen]] RC759 Piccoline
* DDGSXM [[Metafile]]
* EPSMONH6
* IBMHP743 Hewlett-Packard 7470A/7475A Plotter (see DDHP7470 and DD7470)
* METAFIL6 [[Metafile]]
* PALETTE [[Polaroid camera]]<ref name="DRI_1984_MicroNotes2"/>

The [[DOS]] version of GSX supports loading drivers in the [[CP/M-86]] [[CMD file (CP/M)|CMD]] format. Consequently, the same driver binary may operate under both CP/M-86 and DOS.<ref name="Lineback_GSX"/>