Maintenance
& Service Guide
Presario 7900 Series Personal Computers
Models: 7922, 7930, 7935, 7940, 7947, 7950, 7970,
7973, 7985
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Specifications
Compaq Presario 7900 Series Personal Computer specifications are listed in the following tables. Select the specification you are interested in from the navigation bar.
| Specifications |
| System Specifications |
| Video Memory |
| System Interrupts |
| System I/O |
| System Memory |
| System DMA |
| Power Supply |
| Diskette Drive |
| DVD Drive |
| IDE Hard Drives |
| Mouse |
| Fax/Modem |
| CD-RW Drive |
System Memory |
|||
| Size | Low Address | High Address | System Function |
| 640 KB | 00000000 | 0009FFFF | Base Memory |
| 128 KB | 000A0000 | 000BFFFF | Video RAM |
| 32 KB | 000C0000 | 000C7FFF | Video ROM |
| 32 KB | 000C8000 | 000CFFFF | unused |
| 64 KB | 000D0000 | 000DFFFF | unused |
| 48 KB | 000E0000 | 000EBFFF | unused Not available for option cards Can use for UMBs |
| 16 KB | 000EC000 | 000EFFFF | 16-bit cacheable,
shadowable, read only memory Not available for option cards |
| 64 KB | 000F0000 | 000FFFFF | System BIOS ROM shadow image |
| 15 MB | 00100000 | 00FFFFFF | Standard Extended Memory |
| 64 MB | 01000000 | 04FFFFFF | Rest of Extended Memory |
| 60 MB | 05000000 | 07FFFFFF | unused |
| 512 KB | 08000000 | 0807FFFF | Standard Direct Video Memory |
| 512 KB | 08080000 | 080FFFFF | Optional Direct Video Memory |
| 1919 MB | 08100000 | 7FFFFFFF | unused |
| 16 M | 80000000 | 80FFFFFF | Memory mapped I/O devices |
| ~2000 MB | 81000000 | FDFDFFFF | unused/System ROM aliases |
| 128 KB | FDFE0000 | FDFFFFFF | System ROM (alias) |
| ~32 MB | FE000000 | FFFDFFFF | unused |
| 128 KB | FFFE0000 | FFFFFFFF | System BIOS ROM |
System DMA |
|||
Default DMA |
ISA Bus Pin |
Function |
Alternative Mapping |
DMA0 |
ECP Printer Port (LPT1) | ||
DMA1 |
Available | ||
DMA2 |
Standard Floppy Disk Controller | ||
DMA3 |
Available | ||
DMA4 |
Direct Memory Access Controller | ||
DMA5 |
Available | ||
DMA6 |
Available | ||
DMA7 |
Available | ||
| U. S. | Outside U. S. | ||
| Input Specifications | |||
| Voltage Switch Setting | 115 V | 230 V | |
| Nominal Line Voltage | 115 VAC | 230 VAC | |
| Range Input Line | 90 to 132 VAC | 180 to 264 VAC | |
| Frequency Range | 47 to 63 Hz | 47 to 63 Hz | |
| Power Factor | 0.55 | 0.55 | |
| Input Power | 310 Watts | 310 Watts | |
| Input Current | 6 at 90 VAC | 3 at 180 VAC | |
| Inrush Current | 65 A at 115 VAC (cold start) |
65 A at 230
VAC (cold start) |
|
| Holdup Time | 16 ms from zero crossing at 120 VAC | 16 ms from zero crossing at 240 VAC | |
| Steady State | 200 Watts | 200 Watts | |
| General Specifications | |||
| Full Output Rating | To 122°F and 5,000
ft To 90°F and 10,000 ft (derate linearly) |
To 50°C and 1524 m To 32°C and 3048 m (derate linearly) |
|
| Minimum Load | 1.4 A on + 5.0 V output;
0.07 A on 12 V output |
1.4 A on +
5.0 V output; 0.07 A on 12 V output |
|
| Ambient Temperature Range | |||
| Operating | 50° to 122° F | 10° to 50° C | |
| Storage | -40° to 151° F | -40° to 66° C | |
| Dielectric Voltage Withstand | |||
| Input to Ground | 1500 VAC/1 second | ||
| Safety Standard | UL 1950; CSA 22.2 950; TUV/VDE EN 60 950 (VDE0805/11.91); EMKO-TSE (74-SEC) 207/94 | ||
| Input Transient Susceptibility | |||
| Common and Differential
Mode (superimposed on AC line) |
2500 V, 1
us, damped sinusoid 600 V, 10 us pulse |
||
| Differential Mode | 20% step change in AC input voltage | ||
Diskette Drive |
|
| Diskettes | |
| Size (in) | 3.5 (8.89 cm) |
| High Density (MB) | 1.44 |
| Low Density (KB) | 720 |
| Light | Green |
| Height | One-third |
| Bytes per Sector | 512 |
| Sectors per Track | |
| High Density | 18 |
| Low Density | 9 |
| Tracks per Side | |
| High Density | 80 |
| Low Density | 80 |
| Read/Write Heads | 2 |
| Average Seek Time (ms) | |
| Track-to-Track | 3 |
| Average | 94 |
| Settling Time | 15 |
| Latency Average | 100 |
CD/DVD Drive |
||
| Dimensions | U. S. |
Metric |
|
5.74 in 1.68 in 8.23 in |
14.60 cm 4.29 cm 20.80 cm |
| Weight | 1.80 lb | 0.9 kg |
| Applicable Disc Formats | ||
|
Mode 1 and Mode 2 Audio Mode 2, Form 1 and 2 Single and Multiple Session |
|
| Block Size | ||
|
2352 bytes 2352, 2340,2336, 2048 bytes 2352,2340, 2336, 2048 bytes 2048 bytes |
|
| Center Hole | 15 mm diameter | |
| Diameter | 12 cm, 8 cm | |
| Thickness | 1.2 mm | |
| Track Pitch | 0.74 µm (DVD) 1.6 µm (CD-ROM) | |
| Laser | ||
|
53.5 degrees ± 1.5 degrees 5 mW Semiconductor laser GaAIAs 650 nm ± 25 nm (DVD) 795 nm ± 25 nm (CD) |
|
| Access Time (Typical) | ||
|
DVD: < 180 ms < 300 ms |
CD: < 120 ms < 200 ms |
| Audio Output Level | ||
|
1.0 V (RMS) at 47 kW 0.7 V (RMS) at 32 W |
|
| Cache Buffer | 512 KB | |
| Sustained
Data Transfer Rate |
150 KB/sec
(single, CD-ROM mode) 2100-4800 KB/sec (32× CAV CD-ROM mode) 4455-10800 KB/sec (8× CAV DVD mode) |
|
| Interface Cable Length (Max) | 18 in | |
| Startup Time | < 10 sec | |
| Stop Time | < 3 sec |
|
