The Social Welfare Department says its central referral system has 138 people waiting for places in eight government and privately run, subsidised hostels. They can accommodate 331 disabled adults - most are full.

The Sha Tin Cheshire Home has a waiting list of more than 20 for one of the 50 beds in its two wards for the severely disabled, but medical experts warn that without rehabilitation those with disabilities, especially the young, can lose the desire to live.

Dr Ip Wei-chung, chief executive of the Sha Tin Cheshire Home, said: ''Some people appear to suffer minor disabilities, but encounter difficulties living in an ordinary house. They may need special help and equipment, for example when they use a toilet.'' He is worried that sending young disabled people such as Mr Tang to privately-run homes for the elderly, which impose no age restrictions on disabled patients, will become a trend.

Almost one in six patients at the Cheshire Home once lived in a private hostel for the elderly and Dr Ip warns that most hostels within the budgets of ordinary families are not up to standard.

But what causes him most concern is the grouping of young disabled people with the elderly - a form of abuse, because the intelligent, alert disabled are unable to develop their potential.

''It's inappropriate and inhumane to send young people with handicaps to old-age homes,'' he said. ''Many of the young with handicaps become very pessimistic when they share a room with the dying - these disabled young people haven't yet reached the age to die.'' The Cheshire Home's nursing officer, Shirley Chan See-lan, said inadequate special training for staff working in homes for the elderly deprived disabled people of the chance to integrate back into society.

''Three meals a day can never make a normal life for the handicapped,'' she said.

In his 18 years at the Government-run hospital, Mr Tang made little progress and was discharged to a Wong Tai Sin infirmary.

''I just stayed in the infirmary overnight and moved to a private home for the aged the next day,'' Mr Tang said.

The three-storey private hostel for the elderly was modestly priced, costing about $2,000 a month. But Mr Tang could think only of death during his days there.

He has only limited movement in his hands and in his first year in the hostel was confined to a wheelchair in his 300-square-foot second-floor room. A mentally disabled, mute co-resident had to get him in and out of bed.

Lack of exercise made Mr Tang drowsy. ''I would fall unconscious just sitting up in my bed,'' he said.

A year later, he was moved to the ground floor. ''I found no one to talk to because most of the aged were very quiet,'' he said. ''I couldn't find a partner to play chess, though I was able to move around in the plot of land in front of the building in my wheelchair.'' HIS greatest hardship was the restriction on the use of fresh water: ''I could only have a bath every two days even in summer. My inability to keep my body cool made me faint often.'' It is a sad comment on the facilities in Hong Kong that, despite his severe disabilities and the hardship he has endured, Mr Tang regards himself as fortunate. If the government-funded home in Sha Tin had not opened, he could still be in the home for the elderly or in hospital.

The South China Morning Post spoke to a number of private hostels for the elderly and found no rehabilitation was guaranteed for disabled residents, despite the fact their applications were seldom rejected.

Most hostels apply no age criterion and residential fees, which depend on the degree of disability of the applicant, range from $4,000 to $5,000 a month, excluding medical expenses and the cost of napkins for those who are incontinent.

The relatively low fees are attractive to families who want to care for disabled members, but are unwilling or unable to spend much on them. The end result is often a roof over their relative's head, but little quality of life.

A member of staff in a home at Aberdeen said they did not screen applicants, but new residents had to give two months' rent as a guarantee. He said they could provide better services than Government-run hostels.

''Every worker in this hostel only has to look after about 10 inmates, while the Government's ratio is one nurse to 20 residents,'' he said.

A nurse in a home in Tai Po, who declined to give her name, said there were five nurses to look after 40 residents. She refused to give examples when asked what special facilities were provided for the disabled.

It's not illegal for them to admit these young people; the Residential Care Homes (Elderly Persons) Bill has no provision forbidding the admission of disabled people under 60.

The Social Welfare Department's spokesman however said people operating homes for the elderly were advised not to admit disabled people who required different care and assistance.

In October 1986 the department established a code of practice for such profit-making homes for the aged, but compliance is voluntary.

Staff at the Registration Office of Private Homes for the Elderly visit the establishments regularly, however the South China Morning Post understands licences are only likely to be cancelled if the homes breach safety standards, such as failing to have emergency exits.

The spokesman said the Government planned to introduce a bill covering all residential care homes for the elderly, including those in the private sector.

In 1992, Mr Patten said a further 3,930 residential places would be provided for the physically disabled, the mentally disabled and those suffering from mental illness by 1997.

But, despite his two decades of virtual imprisonment, Mr Tang's ambitions and faith in himself have not died. ''Now I hope someone could give me an electric wheelchair so I can earn my own living in a sheltered workshop,'' he said.

And the goal is a realistic one; Sha Tin Cheshire Home's nurses say Mr Tang, a student in a computer class for the disabled, can manage a word-processor better than many able-bodied people.