MP-ROM player
| Manufacturer | Macpower peripherals | |
| Origin | Taiwan? | |
| Year of unit | 1999 | |
| Year of introduction | 1999 | |
| Type | Player | |
| Today we listen to MP3s using 
				portable players or smartphones. In 1999 Taiwanese company 
				Macpower Peripherals shown a stand-alone MP3 player with CD 
				drive - the most popular medium for large data in late 1990s.
				 Macpower Peripherals wa sa company who made server racks and server-grade computers, so their first MP-ROM player was installed in a full-height SCSI external enclosure. You can see it in product announcement from Polish Enter magazine August 1999.  | 
				||
| Because server-like enclosure was just not 
				appropriate for high-end audio set or even an average radio 
				equipment in typical living room, European importers wanted 
				another, more user-friendly casing. It was quickly re-designed 
				to be more compact and use external power supply unit. One of 
				importers was German Conrad electronics who still offer
				
				manual to download. To listen to music, headphones (using front-panel connector) or amplifier (using cinch connectors on the rear) may be used.  | 
				||
It is important to supply proper voltage (12V) with positive tip plug. if not, internal fuse may blow.
		
		1 - GND
		2 - +12V DC 1-1.5A
		Using external 12V (1-1,5A) power supply unit forced whole electronics 
		to be re-designed adding 5V converter on-board. This is known as Model 
		0005. My unit is quite early, it has drive from 1998. 
		
		All display is made using 4-digit 7-segment display and LEDs displaying 
		mode and play status.
During playback, only ambiguous track number is displayed, 
		so having a CD full of MP3s in fancy directory tree gives chaos. I 
		suspect the player orders files not by tag, but by their position in 
		table of contents in CD's ISO filesystem. 
		The software in microcontroller driving display and track selection also 
		doesn't look good. Some routines look like have been written together 
		for debugging and not separated in release version... or maybe my MP-ROM 
		player is just very early.
		Example: When CD is inserted player looks in CD's table of contents for 
		MP3s, their count is displayed on 7-segment display to indicate 
		progress. Unfortunately modifying microprocessor's internal table of 
		tracks is permanently connected with displaying them and display 
		refresh, so after removing CDs clearing this table results in few 
		seconds of mess in display.
		I think instead of linking another gallery I'll describe here what is 
		inside the player.
		
		After removing cover it can be seen that there's a normal IDE CD-ROM 
		drive, Mitsumi, 24x. All electronics is located below, cooling has been 
		made using holes in rear.
		
		Here's the mainboard. Upper-left part is voltage converter module. Below 
		is CPU with its chips, moving right MP3 decoder and remote control 
		drivers. Looking lower-left we can see analog part.
		
		Here is the CPU, a W78E52 microcontroller with two Atmel PLDs as glue 
		logic and 32kBytes of memory in IS62C256 chip. Rest of chips are glue 
		logic. In distance there's Micronas MAS3507D chip which is the main MP3 
		decoder.
		
		Display/User interface part. Many things are implemented using TTL 74xx 
		chips, maybe because of poor microcontroller program. Here you can also 
		see Jacs IRDC360 IR remote control chip. Its parameters are not present 
		on manufacturer's site, but IRDC36x were NEC 6121-standard decoders. The 
		closest thing is
		IRDC362 
		datasheet.
		
		Here is analog part, from left: PT2255A volume controller, unidentified 
		chip and PT2308 headphone amplifier. The connector comes from CD drive 
		and is used to play Audio CDs using drive's own routines.