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Text File | 1997-09-07 | 23KB | 471 lines

Originally posted by: GEnie Mail: WM.H.PRICE Bill Price 126 Casmar St. SE Vienna, VA 22180 (703) 560-2684 MULTISYNCH MONITORS COLOR AND HIGH RESOLUTION MONOCHROME DISPLAY FOR THE ATARI STs COLOR BETTERS THE ST'S SC1224 Most multisynch monitors, but not all, will work with the ST's RGB output and vertical refresh rate. Advantages are operation in high resolution monochrome and both low and medium color using a single monitor. An additional advantage is the better color rendition with more differentiation in tonalities. Subtle shades are better represented than on the ST. With Sony color monitors, the colors are Kodachrome in quality -- rich and saturated. On the negative side, none of these color monitors will match the sharpness of the Atari SM124 monochrome monitor. This monitor, as with other monochromes, uses single pells or pixels to represent screen images. Color monitors must use three (Red, Green, and Blue) to form the same point on a screen. As a consequence, they cannot give the crispness and detail. THE CRITICAL TEST -- MONOCHROME SHARPNESS If you use monochrome most of the time, as many do with Spectre Macintosh emulation, the major question is whether or not a softer and coarser monochrome display on a color monitor is acceptable for continuous use. It doesn't make sense or cents to buy one of the lower priced multisynch monitors as an economy measure just to obviate the need for two monitors where high resolution monochrome is important. And the purchase of a higher quality and higher priced monitor in the $600 to $650 range -- such as the Sony 1304 HG or NEC 3D may not make much economical sense either. However there are those who continue to have the desire for these types of monitors -- unfortunately, I am one. MONITOR SWITCH BOX -- ROLL YOUR OWN The following pages give pinouts and wiring diagrams for construction of a Monitor Switch Box so that a multisynch can be used in both color and monochrome with the ST's monitor output. The box is needed to ground the Monochrome Detect line from the ST and force it to boot in high resolution monochrome. It also switches from the ST's RGB color output to Monochrome Intensity output to drive the monitor. The pinouts for all three Sony monitors (1302, 1303, and 1304) are the same. NEC monitors such as the Multisynch and Multisynch II use the same pinouts. Where Sony and earlier NECs use DB-9 inputs, the new NEC 3D uses a DB-15 connector. The NEC pinouts shown are still valid for the 3D. A converter cable -- DB-9 to DB-15 supplied by NEC -- will give the proper interface. This converter is also availabe commercially as a one piece plug unit. Other monitors, such as the Mitsubishi Diamondscan, use different plugs. The Mitsubishi uses a DB-25 which is the same in pins and shell as an RS-232. The ST's output can be routed to these monitors with the proper pinouts and plug. The Monitor Switch Box can be wired for any monitor output configuration. If another monitor is used, a simple conversion plug is comercially available to reconfigure outputs if both monitors use DB-9 plugs. If plugs are different for two monitors, then wire a cable with the two different terminations. The least effort and highest cost approach is to buy a cable with one of the plugs already made up. If you are good with a soldering iron, then buy the connectors and makeup your own cables. The ST 13-pin DIN plug is not that easy to work with. The solder or rear side has pins just like the front, and soldering wires to these contacts is not a snap. ST monitor cables, with a DIN 13 male on one end and unterminated on the other, are available from two or three sources. Try Best Electronics or Practical Solutions. A 4-pole, double throw switch (On-On) will be required for the Box. Also fit the Box with an RCA jack if you want sound routed to a stereo or self amplified speaker like those available from Radio Shack. If you have Tweety Board, this will not be needed. MARKET FAILURE OF SWITCH BOXES There have been several attempts to market these monitor switch boxes, and all but the most recent have not met with success. The first reason is high price. The first box produced was overpriced in the $200 range. The second reason is differences in pinouts and plug configurations for the variety of monitor inputs. There is no standard. The third reason for lack of success is the small ST market for alternative multisynch monitors. Making your own box for $35 or less in parts will give you an opportunity to try out several monitors at a dealer and select the one that is most acceptable for high resolution monochrome display. But a problem is that most dealers don't have the more expensive monitors broken out for display, and you may not be able to give one a try. Be persistant. Ask the dealer if he can recommend a customer that has a monitor you are interested in. But by all means, try before you buy to insure that the display meets with your satisfaction. Don't take the word of others because each has different levels of acceptability. MULTISYNCH MONITOR PERFORMANCE I have tried the homebrew Monitor Switch Box with the Sony 1303 and the NEC Multisync and Multisync II. The 1303 is not the quality of the 1302 which has a finer dot pitch. However, the color was excellent but the monochrome display was soft. The Sony 1302 has a .26mm dot pitch. This is a measure of the center-to-center distance between dots and is also an indicator of dot or pixel size. Until recently, the 1302 had the finest dot pitch of any color monitor on the market. And dot pitch is a better indicator of sharpeness than horizontal and vertical lines of resolution. The lines are also a function of screen display size; so don't be mislead by more lines resolution. It simply might correspond to a larger monitor display size. And as the monitor size increases, the dots are made larger and render a less sharp display. But Sony is less than forthcoming in its specifications for the 1302. While touting the .26mm dot pitch, they don't publish the fact that this applies to horizontal spacing only. The vertical spacing is different, perhaps .32mm which is nothing to shout about. As a consequence, you may see black horizontal lines that separate the color display lines. They are not dramatically obtrusive, but they are there. On the plus side, the Sony's have that superb Kodachrome color that is richly saturated. The blacks are black, and the background in monochrome is absolutely paper white. The 1302 is satisfactory for ST monochrome use. This model is being superseded by the new 1304 HG that has a .25mm dot pitch. The specifications on this new monitor closely match those of the Apple Color Monitor for the Mac II. This monitor is made by Sony to Apple's specifications, but it is not multisynch. I use one on a Mac II and it is excellent in both monochrome and color. Because of the closeness in specifications -- the only two monitors available with a .25mm dot pitch -- I strongly suspicion that they are the same. Sony has simply adapted the Apple version for multisynch use. And if I were to place my money on a monitor that would be highly acceptable for monochrome display with the ST (sight unseen in an actual test), it would be the Sony 1304 HG. When viewed in color on an IBM PC, the dots appeared extremely fine and it appears that the .25 pitch holds true for both vertical and horizontal. The 1303 is not as good as the 1302 or 1304. However it did give a good monochrome display that was similar in size to the ST's color display in medium resolution. Although good, it does not come close to matching quality of the SM124. Since I spend at least 60 percent or more of my time in Spectre/Macintosh operation, I felt that this was not acceptable for my requirements. When switching from color to monochrome, the screen picture sizes must be readjusted. When the color picture fills out the screen, the monochrome picture will be half screen size until it is adjusted. The Sony controls are in the rear, making them very inconvenient for this operation. The NEC and NEC II have their controls on the front. When making adjustments, insure that horizontal positioning is correct. When first tested, the NEC seemed to have ghosting with the character display. However this was because the screen had wrapped around and required proper positioning. The NEC display was also good. But it was not the equal of Sony in color -- more pastel and less saturated. Both the Sony 1304 and NEC 3D now have automatic screen sizing when displays are changed; so this should eliminate annoying adjustments. Additionally, both are improved over earlier models. Both would perhaps make acceptable choices for monochrome use on the ST. But I would still think that the Sony 1304 would win by more than a hair if it is anything like the Apple Macintosh monitor. Perhaps a dealer will break one out for testing when they become more plentiful and prices drop. Sony 1304s are discounted for around $645, and 1302s for $575. NEC 3Ds are lower priced at $585. The Mitsubishi Diamond scan can be found at $499 and sometimes lower. If the 16" Nano FlexScan is a true multisynch, those who want everything can get it for just under $900. EDITOR'S NOTE: These prices were for new monitors in 1990; you should be able to buy any used monitor for well under $200 in 1996. The following should get you started on a switch box so that you can perform your own acceptance testing. I have not tried a Princeton Graphics or Mitsubishi Diamondscan since I felt that their displays with the IBM PC were not the match of the Sony or NEC. It wasn't worth the money or effort for such a change, and a promise was made a long time ago not to compromise and throw money at something you wouldn't be satisfied with. Climbing out of that hole is too costly, and I have paid this price in both camera and stereo equipment -- but never again. PINOUTS FOR: ATARI ST MONITOR DIN 13 SONY DB-9 NEC DB-9 FUNCTION ST SONY NEC --------------------- -- ------------ ------------ Audio Out 1 NU NU RF 2 NU NU TTL 3 NU NU Monochrome Detect (Switched)4 COLOR NU NU MONOCHROME 1 6, 7, 8, 9 Audio In 5 NU NU GREEN (Switched) 6 COLOR 4 2 MONOCHROME NU NU RED (Switched) 7 COLOR 3 1 MONOCHROME NU NU Ground NU 8 NU NU Horizontal Synch 9 8 4 BLUE (Switched) 10 COLOR 5 3 MONOCHROME NU NU Monochrome Intensity (Sw) 11 COLOR NU NU MONOCHROME (RGB Inputs) 3, 4, 5 1, 2, 3 Vertical Synch 12 9 5 Ground 13 1 6, 7, 8, 9 NOTES: Sony 1302, 1303, and 1304 use the same pinouts. The above can be used for the NEC 3D with a DB-9 to DB-15 conversion cable supplied as standard with the 3D. ST 13-pin DIN cables with male DIN and unterminated at the other end and DB-9 plug/unterminated are commercially available. EDITOR'S NOTE: Try Best Electronics in North America - or, if you have a broken SC1224, "steal" the monitor cable from it. You will need to add a couple of extra wires for monochrome use in that case. The NEC DB-9 to DB-15 converter can also be purchased seperately. If problems are encountered with the NEC 3D, try disconnecting some of the grounds on pins 6, 7, 8, and 9. ST MONITOR 13-PIN DIN CABLE MALE FACE ------------------------------------- Audio Out NU TTL Mono Detect 1 2 3 4 Audio In GREEN RED Ground 5 6 7 8 Horiz Syn BLUE Mono Vert Syn Intens 9 10 11 12 Ground 13 SONY DB-9 PLUG TO MONITOR - MALE FACE ------------------------------------- Ground NU RED GREEN BLUE (COLOR) and and and and MonoDet MonInt MonInt MonInt (MONOCHROME) 1 2 3 4 5 NU NU Horiz Vert 6 7 8 9 DB-9 CONVERSION PLUG FOR SONY TO NEC SONY NEC ---- --- Ground 1 6, 7, 8, 9 Mono Detect NU 2 NU RED 3 1 Mono Intensity GREEN 4 2 Mono Intensity BLUE 5 3 Mono Intensity NU 6 NU NU 7 NU Horiz Synch 8 4 Vert Synch 9 5 This plug is available in most electronic supply stores. One end is DB-9 Female for connecting to the box's output cable, and the other end is DB-9 Male that plugs into the Monitor or the DB-9 to DB-15 cable for the NEC 3D. The converter has a small printed circuit board with jumper wires to make the proper input/output configuration. The pinouts shown above are for a switch box wired for Sony output and their conversion to output configuration for a NEC monitor. MULTISYNCH SWITCH WIRING ST DIN 13 OUT TO SONY DB-9 4-POLE DOUBLE THROW ON-ON 68 Ohm ____________VVVVV_______________________________ | | | | | 100 Ohm | | | | ________________VVVVV___| | | | | | | | | | | .....|..........|........|........|..... | | : | | | | : | | : GROUND MONO MONO MONO : <-- SWITCH | | : | INTEN INTEN INTEN : | | : | IN IN IN : | | : |____________________________________________ | | : _______________________________ | | | : | ___________________ | | | | : | | : | | | | | : | | ______ | | | | | : | | | :| | | | | | ______MONO RED GREEN BLUE :| | | | | | | : DETECT OUT OUT OUT :| | | | | | | : :| | | | | | | : :| | | | | | | : RED GREEN BLUE :| | | | | | | : IN IN IN :| | | | | | | : | | | :| | | | | | | :...............|........|........|....:| | | | | | | | | | | | | | | | | > > > | | | | | | | 68 Ohm > > > | | | | | | | > > > | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ..................................................... ............... : | | | | | | : : | | | | : : 11 13 4 7 6 10 : : 5 4 3 1 : : : : : : ST OUTPUT PINS : : DB-9 INPUT : : : : : : HORIZONTAL SYNCH 9---------:-:--8 HORIZ : : : : : : VERTICAL SYNCH 12---------:-:--9 VERT : :...................................................: :.............: Center poles of switch (labeled as RED, GREEN, and BLUE OUT) are common output to the Sony monitor through the DB-9 connector. When switch is thrown to COLOR side (lower contacts), the ST's RGB output is fed to the common output center poles. Monochrome Detect has no output in COLOR. With the switch thrown to MONOCHROME (upper contacts), Monochrome Detect is grounded and Monochrome Intensity is fed to the three RGB outputs. Horizontal and Vertical Synchs are fed straight through from the ST to DB-9 connector. Thanks to Mike Odegard for the original circuit in file #5617 uploaded in January 1988. It works much better than my circuit that didn't use resistance. MULTISYNCH MONITIOR SPECIFICATIONS DOT BAND SCAN RATE DIAG PITCH PIXLES LPI WIDTH MONITOR SIZE mm HxV HxV MHz HORIZ VERT ----------- ---- ----- ------- ------ ----- ------ ----- Atari Color Medium Res 12 640x200 128K Low Res 320x200 64K Atari Monochrome 12 640x400 256K Sony CPD-1302 13 .26 900x560 30 50-100 15-34 504K NEC Plus 13.5 .33 960x720 94x94 55 56-80 22-45 691K NEC II 13 .31 800x560 81x79 30 50-80 15-35 448K NEC 2A Won't Synch with ST NEC 3D 13 .28 640x480 45 50-90 16-38 Princeton Ultrasynch 11.5 .28 800x600 30 45-120 15-35 480K Mitsubishi Diamondscan 13 .31 800x600 30 45-90 15-36 480K Apple Mac 13 .25 640x480 23 Sony 1304HG 13 .25 1024x768 28-50 15-38 NOTE: Although the NEC 3D will display 1024x768 resolution, it must be driven by an IBM 8514/A card for interlaced input. Supposedly the Sony 1304 will display the above resolutions in multisynch mode. The Macintosh resolutions are for non-interlaced display. Call Sony on 1 800 222-0878 for more information and specifications.